Submission #3999: £e_Nécroyeur's NES Iron Tank: The Invasion of Normandy in 11:47.48

Iron Tank: The Invasion of Normandy is an action game released by SNK in 1988. It continued SNK's trend of military-themed action games such as Ikari Warriors and Guerrilla War. I was not a big fan of these earlier titles, but SNK took the best part of these games--driving a tank--and developed an entire game based on the idea. Now that's more like it!

While Iron Tank is moving, its tank tracks cycle through 4 different statuses in sequence. When this "Track Status" is ideal (basically every 4th Frame of animation), Iron Tank can change direction much more quickly. Iron Tank can make a 45 degree direction change with just 1 Frame of delay, compared to as many as 4 Frames of delay un-optimized. Thus, Iron Tank can make a 45 degree direction change and begin moving in the new direction in just 3 Frames, compared to as many as 6 Frames un-optimized. This is exploited throughout the TAS, saving over 100 Frames in total. Track Status is also one of the biggest difficulties in making a TAS of this game. Iron Tank's Track Status changes each time a joystick direction is pressed, regardless of whether or not Iron Tank actually moves (changes X/Y position). In attempting to correct an earlier mistake in the TAS, even 1 Frame of extraneous input will alter the Track Status and cause the next direction change to be out of sync, ruining the TAS.

Most of the Boss enemies in the game explode with a lengthy "flashing" explosion when they are destroyed. In this TAS, all but 2 Boss enemies are prevented from exploding in this way, saving a substantial number of Frames. This is achieved by moving and firing in a specific manner (sometimes seemingly at random). This technique is used, where possible, throughout the TAS, saving over 1000 Frames in total. Note that this technique does not work against the Boss of Area 1 or the Boss of Area 4.

Rotating the Main Cannon turret is normally done by holding the B button plus the desired direction with the joystick until the turret has rotated. This can take as many as 8 Frames to rotate the turret 45 degrees. However, if the B button and a direction are pressed for just 1 Frame, with the B button released on the following Frame, the turret will rotate 45 degrees in the desired direction in just 2 Frames. That's 8 Frames to rotate the turret 180 degrees, compared to 25 Frames unoptimized. This technique is used to strike targets in multiple locations as quickly as possible, and also for "dancing".

In some areas (particularly Airbase and Headquarters), Iron Tank's X position determines which enemies appear, and where.

If there are too many objects (enemies, items, projectiles) on the screen, some enemies and some items will not appear.

Destroying enemies and collecting items on a specific Frame can provide a more favorable result as Iron Tank advances to the next enemy spawn point. Destroying enemies and collecting items at the last possible moment is generally preferred for purposes of manipulation, because it allows fewer new enemies to appear, and it minimizes the Lag from Iron Tank's projectiles by keeping a very short firing distance. However, depending on circumstances, it may be better to act on the earliest possible Frame, or even a particular Frame in between (though it may seem counterintuitive to do so).

Firing the Machine Gun before (even hundreds of Frames before) the next enemy spawn point is reached can determine whether or not an enemy spawns, as well as the enemy's initial behavior. The specific results will vary, depending upon which Frame the Machine Gun was fired, and changes every 40 Frames or so.

Simply having a Machine Gun projectile on the screen when an enemy spawn point is reached can determine whether or not an enemy spawns, as well as the enemy's initial behavior.

Rotating the Main Cannon before (even hundreds of Frames before) the next enemy spawn point is reached can determine whether or not an enemy spawns, as well as the enemy's initial behavior. An example of this can be seen at Frame 10606, where it is used to manipulate the Louis tanks to stay clear of the movement path but stay on the screen long enough to prevent an additional Louis from spawning.

The specific Frame on which an enemy spawn point is reached can determine whether or not an enemy spawns, as well as the enemy's initial behavior. As such, a delay of just 1 Frame (so that the spawn point is reached on Frame 110 rather than Frame 109, for example) can be enough to alter which enemies appear in the next area, as well as their initial behavior. Of course, a longer delay might be needed to achieve the desired result, but such a delay may still save time overall by manipulating more favorable enemy behavior, or by reducing Lag.

A delay of just 1 Frame or a direction change of 1 pixel can be enough to manipulate the behavior of onscreen enemies. In addition to other things, this can be used to "bait" an enemy into following Iron Tank more closely, which can prevent new enemies from spawning.

Pressing diagonally along a parallel vertical wall (rather than just pressing up to move alongside it) can alter which enemies appear in the next area. It can also be used to manipulate the behavior of onscreen enemies. For example, pressing Up and Left along a wall may convince an enemy to pursue to the left, though Iron Tank is actually only moving straight up. Note that this technique can cause Lag.

In Area 3 - Power Plant and Islands, there are a number of electrical field barriers. If Iron Tank makes contact with one of these barriers, it would be quickly destroyed. These electrical field barriers last for 127 Frames after the 1st Frame the barrier appears onscreen, after which the barrier shifts to the next set of terminals for 127 Frames, at which point the process repeats. Iron Tank's X position may also cause an electrical field barrier to shift before the counter has expired; in such an event, the barrier will simply shift again normally when the timer expires. If Iron Tank touches the electrical field barrier, or the electrical field barrier is hit with any weapon, the counter will be reset. In this TAS, the Main Cannon is fired at several of these electrical field barriers to manipulate their timers and thus make faster progress. Not every electrical field barrier is manipulated due to the constant need to conserve Main Cannon Bullets.

If a Main Cannon projectile hits an enemy tank on its extreme outside edge, it is possible for the projectile to destroy the tank while avoiding its solid "core" (see elsewhere in this document), thus allowing the projectile to continue to move along its path until its range limit is reached (or it hits another target). This is used a few times in the TAS to destroy multiple targets with 1 Main Cannon projectile, most notably to destroy several walls while destroying enemy tanks with the same shot. This was instrumental in conserving Bullets while still keeping things moving as quickly as possible.

There is a 1 Frame delay of forward movement every time the turret position changes (e.g. turns), unless the turret position is being changed to match the Tank's direction of movement, or the Tank is pressing against a solid object, and the turret is being turned toward the solid object. However, during diagonal movement, Iron Tank can take advantage of the "pause" Frame to rotate the Main Cannon without any additional delay. Rotate the Main Cannon on the 2nd Frame after the "pause" Frame while moving diagonally. The Main Cannon will rotate 45 degrees while Iron Tank still has 1 Frame of forward momentum prior to the next "pause" Frame, thus no Frames of forward movement are lost.

There may be more or fewer Frames of Lag during certain screen transitions, depending on the Frame on which the transition began, Iron Tank's X position, the controller input during that Frame, and the objects on the screen. The difference between the ideal result and the worst result can be as many as 36 Frames. The amount of Lag can be manipulated by holding buttons or by holding the directional pad in some direction. Holding a combination of buttons and directions also works. Naturally in this TAS, the length of these transitions have all been manipulated to be as short as possible. This affects the following situations:

Starting a new game

Entering the Sub-Screen

Exiting the Sub-Screen

Entering a new game map area (e.g. the transition while entering Area 4 - Naval Base)

Pressing directly against a corner of an obstacle will cause Iron Tank to automatically correct its path around the corner (without having to manually turn Iron Tank), provided the Tank is within 1 pixel of the edge of the corner. Sometimes this can occur very quickly--as little as just 1 Frame of delay--so it often saves time compared with turning the Tank manually on the correct Frame. Furthermore, because the initial 45-degree turn caused by pressing against a corner of an obstacle is instantaneous, it can be used to begin a 45-degree turn without Frame loss.

Having a Machine Gun projectile on the screen when the Main Cannon is fired may somewhat alter whether or not the Main Cannon projectile hits a target (plus or minus 1 pixel). This can also be manipulated by pressing the A and B buttons on the same Frame, by pressing the B button 1 Frame earlier than the A button, or by firing the Machine Gun on a specific Frame while a Main Cannon projectile is already on the screen. This technique can be used to destroy a target on an earlier Frame, or to manipulate a "glancing blow" against a target.

There are many power-up items (referred to in the game as Bullets) scattered throughout the game which provide various enhancements to Iron Tank's Main Cannon projectiles. It is critical to the overall speed of the TAS that Iron Tank has every type of these Bullets enabled when destroying the many Boss enemies in the game. Unfortunately, these Bullets must be enabled via the Sub-Screen (the game's Sub-Screen), which consumes a considerable amount of time (well over 100 Frames). Furthermore, if the supply of any of these Bullets reaches 0, that Bullet type will be disabled, and even if more Bullets of that type are collected, it would still have to be re-enabled in the Sub-Screen. To make matters worse yet, the supply of these items is rather limited, and even more limited along a direct path. To deal with these issues, the Sub-Screen is only accessed 3 times in this TAS: 1st before the Area 1 Boss, 2nd at the beginning of Area 2 (necessary to prevent completely running out of B Bullets), and 3rd toward the end of Area 3 (both to re-enable B Bullets, and also to enable the R Item, which allows Iron Tank to survive running over a mine in order to take a major shortcut). Also, only a bare minimum of Items is collected, and those which are collected off the most direct path have been carefully chosen for minimal deviation from the direct path. Of course, this also means minimizing the number of Bullets fired, and every effort has been made to do so. Because the default Main Cannon projectile has an infinite supply of ammunition, and no Bullets are enabled until just prior to the boss, Area 1 is one of the most entertaining segments in the game as every possible target is destroyed.

The Machine Gun does 1 damage per shot. The projectile travels slightly more slowly than the Main Cannon's projectile, arriving at maximum range about 6 Frames later than a Main Cannon projectile. When it is fired vertically or horizontally, it has a slightly longer range (about 10 pixels longer) than the Main Cannon. When it is fired diagonally, it has a slightly shorter range (about 6 pixels shorter) than the Main Cannon. If the Machine Gun is fired at a destructible wall while Iron Tank is moving, the wall may not take damage as it should. After the Machine Gun has been fired, it cannot be fired again until after the hit animation sprite has disappeared (or sometimes in laggy conditions, on the last Frame of the hit animation sprite).

The Main Cannon does 4 damage per shot by default. The Main Cannon's projectiles can be enhanced by various power-up items (referred to in the game as Bullets), enabling the Main Cannon to do up to 12 damage per shot. The Main Cannon may have a very slightly longer range (plus or minus 1 pixel), depending on the Frame on which it is fired. Having a Machine Gun projectile on the screen when the Main Cannon is fired may somewhat alter whether or not the Main Cannon projectile hits a target (plus or minus 1 pixel). Entering any control input while a Main Cannon projectile is in flight may somewhat alter whether or not it hits a target (plus or minus 1 pixel). When it is fired vertically or horizontally, it has a slightly shorter range (about 10 pixels shorter) than the Machine Gun. When it is fired diagonally, it has a slightly longer range (about 6 pixels longer) than the Machine Gun. The Main Cannon can be fired again on the last Frame of the projectile's explosion animation.

V allows the Main Cannon to have 3 projectiles on the screen simultaneously.

L increases the maximum range of the Main Cannon by roughly 80%; from 80 pixels to 144 pixels for a vertical or horizontal shot, and from (63 X and 63 Y) pixels to (113 X and 113 Y) pixels for a diagonal shot.

F adds 4 damage to the Main Cannon. It also allows the Main Cannon projectile to penetrate (e.g. fly straight through) any background obstacles (e.g. trees and hills) as well as certain enemy targets. These targets include doors, Foot Soldier, Officer, and Gustafu medium armored tank (green). All other enemy tanks have a solid "core" at their center which prevents penetration from a direct hit. Any target that is penetrated by the projectile will take damage. There is no decrease in the projectile’s damage after it has penetrated a target. If an F projectile hits at a point where 2 or more enemies overlap, the damage may be applied to the unintended target.

B fires a 2nd projectile simultaneously with the Main Cannon projectile, so it appears to be just 1 projectile. This projectile does 4 damage, and explodes on contact, damaging anything within the radius of the explosion. The explosion lasts for several Frames. There is 3-Frame delay between the initial Main Cannon damage and the B damage. B also slightly increases the effective range of the Main Cannon, due to the large explosion sprite; however, if only the explosion sprite reaches a target (and not the Main Cannon projectile), it will only do 4 damage. With B enabled, if a target is hit with a glancing blow (e.g. the edge of a tank's track), and the damage incurred by the Main Cannon (or F) projectile is sufficient to destroy it, the target will be destroyed, but the B projectile will continue to move along its path until its range limit is reached (or it hits another target). If the attack was a glancing blow, and the B projectile continued through the initial target, the projectile will do only 4 damage if it hits another target.

Foot Soldier has 1 Hit Point and does 1 damage per shot. Though they can be destroyed by any means (even a single Machine Gun shot), Iron Tank can destroy these by simply coming into direct contact with them, and Iron Tank will not take damage from doing so. Every Foot Soldier destroyed by direct contact restores 2 Hit Points to Iron Tank.

Officer has 1 Hit Point and does 1 damage per shot. Every Officer will drop a V item when it is destroyed. Though they can be destroyed by any means (even a single Machine Gun shot), Iron Tank can destroy these by simply coming into direct contact with them, and Iron Tank will not take damage from doing so. Every Officer destroyed by direct contact restores 2 Hit Points to Iron Tank.

Louis light armored tank has 3 Hit Points and does 1 damage per shot. Louis is armed only with a Machine Gun, and as such does 1 damage per attack.

Gustafu medium armored tank (green) has 4 Hit Points and does 4 damage per shot. Because the Gustafu has no secondary collision box when it explodes (see above), Iron Tank can ram straight through them for only 4 damage. Furthermore, with F enabled, any Main Cannon projectile that hits a Gustafu will destroy it, and then continue to move along its path until its range limit is reached (or until it hits something more solid).

Becks Haus heavy armored tank and Waltar medium armored tanks (Waltar has the same sprite as Gustafu, but colored silver with a gold turret) have 8 Hit Points and do 4 damage per shot.

Hans turret has 8 Hit Points and does 4 damage per shot. These are the domed turrets found mounted on walls and such throughout the game, most prominently in the last area of the game. These enemies are stationary but can rotate like any other turret in the game. Because they are stationary, they have less to "think" about, making them less prone to AI manipulation, and more effective overall. This, combined with a long-range, rapid-fire attack, makes them one of the most dangerous enemies in the game. At several points in the last area, these are manipulated not to spawn.

Submarine has 4 Hit Points and does 4 damage per shot. These are not to be confused with the much larger Venglar-Rank submarine (see below). These enemies appear only in Area 3 - Power Plant and Islands where they emerge from the water surrounding the islands. They fire slow-moving projectiles with a limited homing ability, which in this TAS remain on the screen for a comically long time as they attempt (and fail) to chase Iron Tank. If a Submarine has taken fewer than 4 damage before it has fully surfaced, its Hit Points will be reset to 4 after it has fully surfaced.

Venglar-Rank submarine deck guns have 8 Hit Points and do 4 damage per shot. These enemies appear only in Area 4 - Naval Base. Each Venglar Rank has 2 deck guns which fire long-range, rapid-fire projectiles. Given the circumstances of the area in which it appears (e.g. a narrow catwalk), Venglar Rank is possibly the most dangerous enemy in the game, and certainly in the context of making a TAS. In this TAS, 2 Venglar Ranks are prevented from spawning by manipulation (the Venglar Rank graphics can be seen, and the deck guns can be heard firing, but the deck guns themselves do not spawn).

J-Type Armored Train has 8 Hit Points and does 4 damage per shot.

V-II Missile has 32 Hit Points. Destroying a V-II does not award any points. It does 32 damage, but it must be a near-perfect direct hit on Iron Tank or it will do no damage. Like the ? weapon, when a V-II detonates, all enemy projectiles on the screen are destroyed (except Machine Gun fire), and while it is exploding (while the screen is flashing), any projectiles fired by the enemy are instantly destroyed (except Machine Gun fire), rendering many enemies unable to fire at Iron Tank.

Werner 109K fighter plane does 8 damage per shot and cannot be destroyed. These enemies move vertically across the screen.

Yunkel JU88r-1 fighter bomber plane does 8 damage per shot and cannot be destroyed. These enemies move horizontally across the screen.

E restores 8 Hit Points to Iron Tank, to a maximum of 32 Hit Points. If the R (Reserve Fuel) Item has already been collected, and an E Item is then collected that would bring Iron Tank's Hit Points above the maximum of 32, the extra Hit Points are added to Iron Tank's R (Reserve Fuel) Item, to a maximum of 32 Hit Points. For example, at full (32) Hit Points, collecting an E Item would add 8 Hit Points to Iron Tank's R (Reserve Fuel) Item; at 31 Hit Points, collecting an E Item would add 1 Hit Point to Iron Tank, and 7 Hit Points to Iron Tank's R (Reserve Fuel) Item, and so on. Only the R and E items can add Hit Points to the R (Reserve Fuel) Item; running over Foot Soldier or Officers or picking up other items will only add to Iron Tank's current Hit Points.

R restores Iron Tank to maximum (32) Hit Points, and adds the R (Reserve Fuel) Item to Iron Tank's inventory, also at maximum (32) Hit Points. If R is enabled, and Iron Tank takes damage sufficient to destroy it, Iron Tank's Hit Points will be instantaneously restored by the number of Hit Points stored in the R (Reserve Fuel) Item. Only the R and E items can add to the R (Reserve Fuel) Item; running over Foot Soldier or Officers or picking up other items will only add to Iron Tank's current Hit Points.

V restores 2 Hit Points to Iron Tank, and restores 8 shots of the V weapon to Iron Tank's inventory, to a maximum of 40 shots.

L restores 2 Hit Points to Iron Tank, and restores 8 shots of the L weapon to Iron Tank's inventory, to a maximum of 40 shots.

F restores 2 Hit Points to Iron Tank, and restores 8 shots of the F weapon to Iron Tank's inventory, to a maximum of 40 shots.

B restores 2 Hit Points to Iron Tank, and restores 8 shots of the B weapon to Iron Tank's inventory, to a maximum of 40 shots.

Many enemies "turn red" after their "initial" Hit Points have been reduced to 0. This will happen only once per enemy. When an enemy "turns red", it gains 4 "final" Hit Points. If the B Weapon or F Weapon (or both) is enabled, and an attack does more damage than was needed to reduce the enemies Hit Points to 0, the "extra" damage will be applied to the enemy after the enemy has gained the 4 "final" Hit Points from "turning red". As such, if an enemy has 7 "initial" Hit Points left, and the enemy is hit with the Main Cannon with the B Weapon enabled (this would normally do 8 damage), the enemy would first be reduced to 0 Hit Points (-7 Hit Points), and then "turn red" and gain 4 "final" Hit Points, and finally, the 1 remaining point of damage from the attack is applied to the enemy, leaving it with 3 "final" Hit Points.

An enemy tank retains a small, solid "core" for a few Frames after it is destroyed. The only exception to this is the Gustafu medium armored tank (green). This "core" has 9 Hit Points, and it can be destroyed, but after a few Frames, it will simply leave the screen anyway. The core has a very small collision box (much smaller than the tank itself), and is normally not a threat, unless Iron Tank is ramming directly into and through the enemy tank. In this case, Iron Tank may take the additional 9 damage (e.g. Becks Haus 8 Hit Points + 9 "core" damage = 17 damage!), unless Iron Tank rams the target with a glancing blow (e.g. the very outside edge of the enemy tank), or if Iron Tank is moving directly away from the enemy tank at the time of collision. Unfortunately, this "core" will usually prevent Iron Tank's Main Cannon projectiles from penetrating through stronger tanks (e.g. Waltar and Becks Haus), unless the projectile hits with a glancing blow, because the projectile strikes the enemy's solid core after the enemy has been destroyed. Not even with all the special weapons enabled can a Main Cannon projectile do enough damage to penetrate both the tank and its solid core with a single shot; it would have to do at least 18 damage! However, the chance of a glancing blow can be improved somewhat by first damaging an enemy tank with the Machine Gun (just 1 hit is enough), and then firing the Main Cannon for the kill. Using this technique extends the area on an enemy tank that may be hit for a glancing blow by 1 pixel, greatly increasing the likelihood of a glancing blow. The Frame on which the Main Cannon is fired may also determine whether or not a hit is a glancing blow. Entering any input while a Main Cannon projectile is in flight may also determine whether or not a hit is a glancing blow.

A map transition is always ideally 95 Frames long, though this is actually only achieved a few times in the TAS, due to mitigating circumstances (the RNG).

The Sub-Screen takes a minimum of 118 Frames total to enter and exit (51 Frames to open plus 67 Frames to close), excluding any Frames required to select an item. For example, that's at least 236 total Frames to disable and re-enable a Weapon for a Boss fight. Across the 6 Bosses that must be destroyed in the game, a total of 1416 Frames would be spent in the Sub-Screen.

The Boss of Area 1 is Folten. It has 56 Hit Points, so with all Bullet types enabled, 5 Main Cannon shots are required. It is destroyed quickly. Note the lengthy "flashing" explosion when Folten is destroyed--it is unavoidable in this case, but against most other bosses, it is prevented from occurring by manipulation to save a significant amount of Frames.

There is an invisible barrier that prevents Y-axis advancement beyond Folten (until Folten has been destroyed). If Iron Tank arrives at this point on an even-numbered Frame, it will advance by 1 additional pixel compared to arriving on an odd-numbered Frame. This technique is used to destroy Folten 2 Frames earlier.

This is my first attempt at making a TAS. It was more difficult than I had anticipated. It took nearly a year to complete it. I hope my next TAS will go a bit more smoothly!

Frame 62 Press A+B+Start to manipulate minimal transition time

1063 Frames of Lag for cut scene

Frame 1126 Press and hold Up

Frame 1128 First Movement

Frame 1216 Fire at first target (Foot Soldier)

Frame 3523 Fire Machine Gun to manipulate shorter Sub-Screen transition

Frame 3559 Fire Machine Gun to manipulate shorter Sub-Screen transition

Frame 3561 Hold Up and Press Select to enter Sub-Screen and enable Weapons

55 Frames of Lag

Frame 3618 Enter Sub-Screen Lag ends

Frame 3623 Press A+B+Up+Down+Left+Select to enable last weapon and exit Sub-Screen

71 Frames of Lag

Frame 3696 Exit Sub-Screen Lag ends

Frame 3736 First shot fired against first boss (Folten tank)

Frame 3772 Delay here for 1 Frame to manipulate even-numbered Frame at the edge of the invisible barrier for 1 more pixel of Y-axis movement and to destroy Folten 2 Frames earlier

Frame 4077 Hold Up here rather than later to manipulate ideal Track Status for the turn at Frame 4184

Frame 4080 First movement after Folten

Frame 4372 Turn here at X 124 rather than sooner to put Louis in range of the Machine Gun and to avoid ramming a 2nd Louis, thus mitigating much Lag

Frame 4412 Fire Machine Gun to manipulate shorter Sub-Screen transition

Frame 4450 Hold Up and Press Select to enter Sub-Screen and disable B

53 Frames of Lag

Frame 4509 Delay 1 Frame to manipulate shorter Sub-Screen transition

Frame 4510 Press A+B+Up+Select to disable B and exit Sub-Screen

68 Frames of Lag

Frame 4580 Exit Sub-Screen Lag ends

Frame 5096 Turn here at X 124 while Track Status is ideal, then press against the corner of the wall at the start of the train tracks to save a couple of Frames compared to manually turning at X 123 or later

Frame 5806 Fire Main Cannon here rather than sooner for minimum Lag

Frame 7144 Press Up against the corner of this wall to automatically correct around it, then turn manually at Frame 7224 for ideal Track Status for the turn at X 132. This also allows the R item to spawn correctly later.

Frame 7255 Turn here at X 132 to allow R item to spawn correctly later

Frame 7456 Turn to X 127 here rather than later to manipulate ideal Louis behavior

Frame 7867 Destroy Waltar here rather than later to manipulate ideal spawns in the next area

Frame 7876 Manipulate Louis to follow Iron Tank by changing from X 127 to X 129, preventing several Tanks from spawning in the next area and preventing the Lag they would cause

Frame 8071 Hold Up and Left here to press against the wall for 1 Frame prior to turning the corner. This prevents running over the Foot Soldier, which in turn prevents a Becks Haus from spawning.

Frame 8222 Destroy Foot Soldier here rather than sooner to prevent 1 Frame of Lag

Frame 8286 Destroy Foot Soldier here rather than sooner to allow L item to appear correctly

Frame 8710 Turn here to evade Becks Haus as long as possible while moving to X 176

Frame 8725 Destroy Becks Haus as late as possible to prevent Becks Haus from spawning

Frame 9019 Turn here and allow the cliff to automatically correct Iron Tank's direction at X 140 on Frame 9029. Using the cliff to change direction conserves 1 Frame compared to changing direction manually. Moving to X 140 allows Becks Haus to be destroyed with no need for delay to prevent ramming. It also keeps Iron Tank out of range of the 1st Mine, allowing it to move farther forward, and thus allowing it to turn when Track Status is ideal to move out of range of the 2nd Mine.

Frame 9161 rotate Main Cannon here rather than later to prevent Lag

Frame 9167 Turn here at X 84 while Track Status is ideal and press Up against the corner of the cliff to automatically correct Iron Tank's path to X 83

Frame 9208 Turn here rather than sooner to put Becks Haus in range of the Main Cannon while keeping Foot Soldier safe

Frame 9236 Fire Main Cannon at Becks Haus with no Lag, but allow Foot Soldier to flee for more favorable spawns and less Lag in the next area

Frame 9263 Rotate Main Cannon back to forward position here with no Lag and without Foot Soldier being destroyed

Frame 9527 Rotate Main Cannon back to forward position here with no Lag

Frame 9584 Use 1st of 2 "extra" shots to destroy Becks Haus to prevent Lag

Frame 9623 Turn here rather than go between Mines to use wall to automatically correct direction and to be in position to destroy Foot Soldier

Frame 9660, Frame 9709 Destroy Foot Soldier to prevent Lag

Frame 9754 Turn here at ideal Track Status rather than sooner for ideal Track Status on the next few turns

Frame 9927 Rotate Main Cannon here for minimum Lag

Frame 9974 Destroy Hans turret and ram Gustafu to mitigate Lag

Frame 9978 Rotate Main Cannon here to mitigate Lag

Frame 10268 Destroy Foot Soldier from medium distance to prevent Waltar from spawning

Frame 10276 Press B to prevent a Frame of Lag on Frame 10281

Frame 10278 Press B to prevent a Frame of Lag on Frame 10281

The following Frames rotate the Main Cannon to manipulate favorable Louis AI for minimum Lag and to prevent an additional Louis from spawning:

Frame 10606 Press B+Up

Frame 10608 Press Up+Left

Frame 10622 Press B+Up+Left

Frame 10624 Press B+Up

Frame 10642 Press B+Up

Frame 10770 Delay 1 Frame to prevent 2 Frames of Lag

Frame 11069 Destroy Louis to allow F item to spawn

Frame 11227 Rotate Main Cannon without Lag

The following Frames manipulate the next electrical field barrier such that the nearer of the 2 fields is open, saving 9 Frames overall:

Frame 11278 Fire Machine Gun at Foot Soldier

Frame 11314 Rotate Main Cannon no sooner than this Frame

Frame 11315 Fire Main Cannon at Waltar no sooner than this Frame

Frame 11326 Begin turn here to avoid ramming Waltar

Frame 11335 Fire Main Cannon to manipulate far electrical field barrier to remain closed and rotate Main Cannon without Lag

Frame 11368 Turn and fire here for minimum Lag

Frame 11583 Turn here on X 190 to prevent electrical field barrier from suddenly shifting in front of Iron Tank

Frame 11716 Delay here for 4 Frames to allow electrical field barrier timer to expire

Frame 11780 Turn here at X 36 to maintain maximum distance from Becks Haus and mitigate Lag

Frame 11853 Turn here with no additional Lag from the Becks Haus

Frame 11883 Destroy Waltar to allow F item to spawn correctly and to prevent Becks Haus from spawning

Frame 11922 Turn no later than here to prevent Becks Haus from spawning; this conserves a shot compared to Attempt 6. The V item is not worth destroying an additional Becks Haus

12032 Delay here for 1 Frame to prevent 1 Frame of Lag, allowing the electrical field barrier timer to expire 1 Frame sooner

Frame 12040 Delay here for 2 Frames to allow electrical field barrier timer to expire

Frame 12042 Press Down for 1 Frame to allow passing the electrical field barrier 1 Frame sooner

Frame 12196 Hold Down for 2 Frames to manipulate ideal Track Status for turn after F item

Frame 12340 Rotate Main Cannon here without Lag

Frame 12326 Rotate Main Cannon and turn and move to X 137 before advancing forward for minimal Lag through the next area

Frame 12413 Because only 1 Becks Haus spawns here compared to 2 Becks Haus in Attempt 6, the shot was instead used to destroy the other Becks Haus to mitigate Lag

Frame 12556 Use shot conserved at Frame 11922 to destroy Becks Haus to mitigate Lag

Frame 12586 Rotate Main Cannon here without Lag

Frame 13538 Fire Machine Gun at Submarine out of principle

Frame 13579 Delay 1 Frame just prior to taking damage from the Submarine projectile to mitigate Lag

Frame 13676 Pause 2 Frames to cause Gustafu to miss a shot and mitigate 8 total Frames of Lag

Frame 14227 Use last "extra" shot to destroy Patrol Boat to mitigate Lag

Frame 14231 Turn here to X 113 for minimal Lag

Frame 14384 Delay 1 Frame to mitigate 2 Frames of Lag

Frame 14476 Rotate Main Cannon here without Lag

Frame 14572 Destroy Waltar with a later shot to prevent a Werner 109K from spawning

Frame 14576 Destroy Waltar with a later shot to cause Werner 109K to spawn instead of another Waltar. Werner 109K will cause some damage, but there is less Lag overall.

Frame 14942 Turn here on X 91 rather than X 92 to prevent 2 Frames of Lag and 8 damage from a 2nd shot by the Werner 109K

Frame 14921 Turn and fire at Waltar here at X 98 rather than later. This will cause 1 more Frame of Lag, but it also causes a Waltar shot to miss, which saves 2 Frames of Lag and 4 damage.

Frame 14964 Destroy Waltar with an earlier shot for more favorable spawns

Frame 15546 Fire Main Cannon no sooner than here or the Sub-Screen transition will cause the shot to miss the Waltar

Frame 15601 Fire Machine Gun to manipulate shorter transition into the Sub-Screen Screen

Frame 15618 Hold Up and Press Select to enter Sub-Screen and enable B and R

Frame 15685 Hold Up and the A button and press Select to exit Sub-Screen with B and R enabled

Frame 18526 Rotate Main Cannon here before the Main Cannon projectile hits, but do not fire the Main Cannon yet. This prepares the Main Cannon for destroying 2 more turrets, and the Machine Gun fire prevents 1 Frame of Lag from the first fortress turret's explosion. This can be done sooner, but this is the last Frame on which it will work.

Frame 18535 Fire at 2nd turret here to prevent 1 Frame of Lag

Frame 18536 Delay 1 Frame here to prevent 1 Frame of Lag

Frame 18548 Fire at 3rd turret here to prevent 1 Frame of Lag

Frame 18566 Turn for 1 Frame and fire Machine Gun at fortress door, then continue forward

Frame 18619 Delay here until Frame 18621 while Iron Tank is at the correct angle to fire Machine Gun at fortress door

Frame 18886 Press Down for 1 Frame to prevent 1 Frame of Lag

Frame 18916 Fire the last shot at the door with the Machine Gun. Frame 18915 is the earliest Frame on which this technique will work, but it works with the next several Frames as well. Destroying the door at this point prevents the mobile turret's "flashing" explosion, thus preventing 134 Frames of Lag.

Frame 18953 Delay here for 16 Frames to prevent Lag

Frame 18969 Begin to hold Up again

Frame 18972 Delay here for 1 Frame to prevent Lag and to manipulate shorter transition into the next area

Frame 18975 Delay here for 2 Frames to prevent Lag and to manipulate shorter transition into the next area

Frame 19121 Fire Machine Gun to manipulate shorter transition into the next area

Frame 19124 Hold Up for 3 Frames for ideal Track Status on the first turn in Naval Base

Frame 19133 First Frame of transition to Naval Base

Frame 19229 First Frame of Naval Base

Frame 19304 Fire at Foot Soldier no sooner than here; otherwise, the next Foot Soldier will not restore any Hit Points when it is run over

Frame 20174 Rotate Main Cannon here to prevent Lag

Frame 20304 Turn to X 134 no sooner than here for minimum Lag

Frame 20343 Destroy Venglar-Rank deck gun here to allow L item to spawn correctly with minimal Lag, and to prevent some damage

Frame 20719 Delay for 7 Frames to manipulate Waltars to fail their attacks. This conserves just enough Hit Points to survive the final stretch of the Venglar-Rank area. Inglorious, but under the circumstances, no better option could be found.

Frame 21399 Fire Main Cannon no sooner than here to destroy Foot Soldier in addition to Becks Haus. Because of a glitch, running over this particular Foot Soldier will not add 2 Hit Points to Iron Tank without a Frame of delay, so it is no loss to destroy him thus with the Main Cannon.

Frame 21432 Press Up and B for 1 Frame to push up against the obstacle and fire the Machine Gun at the Foot Soldier. This keeps the Main Cannon in the forward position without any delay in movement.

Frame 21475 Turn here while at ideal Track Status

Frame 21487 Turn here at X 130 while at ideal Track Status to put the door in range of the Main Cannon. It is well worth the Frames required to move to X 130 rather than turning immediately at X 139; destroying the door before engaging Boss battleship conserves nearly 100 Frames compared to using the Machine Gun to destroy the door after Boss battleship has been destroyed, and conserves nearly 30 Frames compared to using the Main Cannon to destroy the door after the 1st battleship turret has been destroyed.

Frame 21760 Fire Main Cannon at the door. It is well worth the time to Destroying the door now saves a great deal of time, mostly due to the Lag that would be caused by destroying the door after the boss has been destroyed.

Frame 21908 Turn here while at ideal Track Status. This is the earliest Frame that will allow Iron Tank to automatically correct its direction at X 156 using the center obstacle. Turning here allows Iron Tank to move closer to the 2nd battleship turret for a shorter shot. This also allows the final shot at the 2nd battleship turret to be fired on an earlier Frame, thus destroying the battleship on an earlier Frame.

Frame 22155 Hold Left here and move horizontally to X 108, rather than continuing Up and Left. Advancing any farther vertically will cause less desirable transition times to the next area.

Frame 22165 Hold Up for 6 Frames to orient Iron Tank for the start of the next area

Frame 22172 Press B+Up+Right for 1 Frame to rotate Main Cannon to forward position and to manipulate shorter transition into the next area

Frame 22174 Press Up and Right for 1 Frame to manipulate ideal Track Status for more turns in the next area

Frame 22235 Last Frame of Naval Base

Frame 22237 First Frame of transition to Airbase

Frame 22333 First Frame of Airbase

Frame 22443 Fire Machine Gun at Gustafu out of principle

Frame 22619 Fire Machine Gun at Gustafu out of principle

Frame 22683 Fire Machine Gun at Gustafu out of principle

Frame 22875 Fire Machine Gun at Gustafu out of principle

Frame 23545 Arrive at this corner on ideal Track Status, so hold Up to move around it

Frame 24111 Turn here rather than later to hit Waltar with Machine Gun (out of principle) and to move around the dragon's teeth

Frame 24131 Delay for 2 Frames no later than here to prevent a Yunkel JU88r-1 fighter bomber plane from spawning

Frame 24349 Turn to X 42 no later than here to move clear of the next tank trap and to prevent a Werner 109K from spawning. This must be done between Frame 24341 and Frame 24349, but turning on Frame 24349 causes fewer Lag Frames overall.

Frame 24537 Turn no later than here and allow the tank trap to correct Iron Tank's direction at X 43. This allows the next dragon's teeth to be arrived at during ideal Track Status and pushed around quickly, saving Frames overall.

Frame 24893 Fire the Main Cannon here so the door explosion causes only 1 Frame of Lag

Frame 25583 Fire Machine Gun at bomber's turret out of principle

Frame 25731 Turn here on worst Track Status to cause 4 Frames of delay, which causes the upcoming Gustafu and Becks Haus to miss their shots

Frame 26054 Turn no later than here to cause the large bomber to miss its first shot

Frame 26319 Hold Left here for 1 Frame and then resume holding Up+Left until the exit is reached. This will manipulate a shorter transition into the next area without disrupting the Track Status.

Frame 26334 First Frame of transition out of the hangar

Frame 26435 First Frame of the next map area

Frame 26716 Hold Up+Left for 1 Frame and then resume holding Up until clear of the dragon's teeth. This will ensure ideal Track Status on the next turn at X 188 to get around the next tank trap quickly.

Frame 26955 Turn no later than here to prevent any Werner 109K's from spawning in Iron Tank's path

Frame 27752 Fire Machine Gun to manipulate a glancing blow against Becks Haus

Frame 27781 Fire Main Cannon to destroy Becks Haus and wall 1 with 1 shot from maximum range

Frame 27875 Turn no later than here and allow the sandbags to redirect Iron Tank at X 123 with minimal Lag

Frame 28015 Fire Main Cannon here to destroy wall 2 and to prevent a Becks Haus from spawning. Preventing this Becks Haus from spawning here will also prevent an additional Waltar from spawning in the narrow walled pass ahead, where it could not be avoided. As such, it is not worth destroying wall 2 with the Machine Gun to conserve a Main Cannon shot.

Frame 28210 Turn here at the last possible ideal Track Status for minimal Lag from the Becks Haus

Frame 28223 Turn here at X 132 for ideal enemy spawns in the next area. It must be X 132; turning at X 131 would cause less favorable enemy spawns, and X 133 would put the Waltar on the approach out of range of the Main Cannon.

Frame 28254 Fire Main Cannon at Waltar from maximum range for minimal Lag

Frame 28491 Fire Main Cannon to destroy 2 Gustafu with 1 shot and to manipulate ideal spawns

Frame 28591 Fire Main Cannon to destroy a Gustafu and a Waltar with 1 shot

Frame 29080 Fire Main Cannon to destroy a Gustafu and a Waltar with 1 shot

Frame 29203 Turn here and move to X 76 to run over the Foot Soldier and to mitigate Lag

Frame 29398 Fire Machine Gun at Foot Soldier to mitigate Lag

Frame 29800 Delay 1 Frame here to mitigate Lag and to cause one of the "chasing" Waltars to miss its shot, preventing more Lag and conserving 4 Hit Points

Frame 29963 Fire Main Cannon here to destroy wall 3, damage the center Waltar, cause the left Waltar to miss its shot, and prevent a 3rd Waltar from spawning all with 1 shot for minimal Lag

Frame 30063 Fire Machine Gun at Waltar out of principle without causing Lag

Frame 30082 Fire Machine Gun at Waltar out of principle

Frame 30085 Delay 5 Frames here. Iron Tank will collide with and destroy Waltar on Frame 30086, conserving a Main Cannon shot at the cost of 16 additional Frames compared to destroying Waltar with the Main Cannon. The 5 Frames of delay allow time for Waltar's "core" to despawn, conserving 9 Hit Points compared to ramming straight through Waltar. These extra Hit Points will be needed to survive ramming a Becks Haus later.

Frame 30090 Resume holding Up to advance

Frame 30147 Begin destroying wall 4 with the Machine Gun

Frame 30222 Continue to hold Up until Frame 30225 (pushing against the wall) to ensure ideal Track Status through the next section, allowing for faster progress overall

Frame 30225 Stop holding Up

Frame 30226 Fire last shot with the Machine Gun at wall 4

Frame 30372 Fire Machine Gun at Foot Soldier to mitigate Lag

Frame 30374 Turn here to minimize damage from enemy fire and to run over several Foot Soldiers. Running over these Foot Soldiers both restores needed Hit Points and mitigates Lag.

Frame 30568 Turn here while at ideal Track Status to fit perfectly between the 2 buildings.

Frame 30756 Turn Up here on ideal Track Status to move into position to destroy wall 5 with the Machine Gun. Destroying wall 5 with the Machine Gun conserves a Main Cannon shot at the expense of 24 additional Frames compared to using the Main Cannon to destroy wall 5. It is necessary to conserve a Main Cannon shot to prevent running out of the L item during Area 7 - Headquarters, and this was deemed the best opportunity to do so, in terms of the Frame cost.

Frame 30760 Turn Up and Right here on ideal Track Status to move into position to destroy wall 5 with the Machine Gun

Frame 30764 Fire 1st shot at wall 5 with the Machine Gun

Frame 30820 Continue moving along wall 5 to X 108

Frame 30829 Fire 3rd shot at wall 5 with the Machine Gun

Frame 30843 Fire last shot at wall 5 with the Machine Gun

Frame 30852 Delay here for 5 Frames to prevent a Louis from spawning

Frame 30857 Resume holding Up

Frame 31006 Fire the Main Cannon to destroy both the Louis and wall 6 with 1 shot

Frame 31234 Fire last shot with the Machine Gun at wall 7

Frame 31355 Fire Machine Gun at Gustafu out of principle

Frame 31538 Turn no later than here to mitigate Lag

Frame 31629 Though Iron Tank is not at ideal Track Status, turn here to ensure that the next turn at X 123 is at ideal Track Status, allowing for faster progress overall

Frame 31730 Fire Machine Gun to manipulate a glancing blow against Gustafu

Frame 31734 Fire Main Cannon to destroy wall 8, a Gustafu, and wall 9 with just 1 shot. This saves 10 Frames compared to using the Machine Gun to destroy wall 9.

Frame 31948 Fire Main Cannon to destroy Waltar

Frame 31985 Stop holding Up and Fire Main Cannon at Waltar no sooner than here to prevent a Becks Haus from spawning on Iron Tank's path

Frame 31989 Resume holding Up

Frame 32032 Turn here toward X 127

Frame 32038 Resume holding Up here at X 127. This turn is not made on ideal Track Status; the Frames of delay this causes are necessary to prevent a Becks Haus from spawning on Iron Tank's path.

The following Frames must be executed as described to manipulate the shortest possible transition into the next area:

Frame 32541 Fire Main Cannon at fortress turret 1 at X 161

Frame 32542 Rotate Main Cannon Left before holding Up on Frame 32543 at X 162. This allows the Main Cannon to be rotated with no delay. Frame 32543 Resume holding Up

Frame 32567 Fire at fortress turret 2 and Rotate Main Cannon

Frame 32595 Fire Main Cannon at fortress turret 3

Frame 32621 Rotate Main Cannon

Frame 32623 Fire Main Cannon at fortress door

Frame 32632 Fire Main Cannon at fortress turret 4

Frame 32634 Hold Up and Left

Frame 32640 Delay here until Frame 32641 to prevent 1 Frame of Lag

Frame 32641 Resume holding Up and Left

Frame 32707 Continue to hold Up+Left here until Frame 32708 to ensure ideal Track Status on the first turn in the next area

Frame 32708 Stop holding Up+Left

Frame 32713 Press Up+Right+B to rotate Main Cannon back to forward position

Frame 32734 First Frame of transition to Bunker

Frame 32835 Hold Up and Left to begin moving toward X 99

Frame 32836 First Frame of Bunker

Frame 32847 Turn here on ideal Track Status at X 99 to move clear of the crate

Frame 33315 Turn no sooner than here to cause Hans to miss a shot

Frame 33324 Fire Main Cannon at Hans for minimal Lag

Frame 33325 Rotate Main Cannon without additional Lag

Frame 33335 Hold Up here at X 113 while on ideal Track Status

Frame 33339 Rotate Main Cannon without Frame loss. It is necessary to Rotate the Main Cannon here to prevent causing additional Lag by doing so later, when multiple Becks Haus are on the screen.

Frame 33341 Rotate Main Cannon without Frame loss

Frame 33400 Delay here for 1 Frame to cause the next Becks Haus to fire only one shot

Frame 33512 Turn here for minimum Lag

Frame 33525 Fire Main Cannon at Becks Haus for minimum Lag

Frame 33564 Turn around corner here without Frame loss

Frame 34030 Press B to manipulate a shorter transition into the next area

Frame 34029 Stop holding Up+Down+Left

Frame 34146 First Frame of Boss Think Tank (C-Type)

Frame 34684 Turn toward X 124 no later than here for a safe path. This is the last Frame on which to turn that will also put the Foot Soldier in range of the Machine Gun.

Frame 34685 Fire Machine Gun at Foot Soldier. Destroying this Foot Soldier manipulates ideal enemy spawns. Destroying this Foot Soldier on the latest possible Frame prevents 1 Frame of Lag and eliminates the need to delay a Frame to avoid ramming Becks Haus as Iron Tank moves past it.

Frame 34737 Fire Machine Gun at Becks Haus out of principle

Frame 34766 Fire Machine Gun at Becks Haus out of principle

Frame 35070 Fire Machine Gun at Gustafu. This Gustafu will be rammed anyway, and there is no real need to conserve Hit Points here, but firing here causes no additional Lag, and why give up more Hit Points than necessary?

Frame 36258 Fire Machine Gun at Foot Soldier. Whether Foot Soldier is shot or run over, the Hit Points result is the same, so the Machine Gun was chosen for dramatic effect.

Frame 36394 Fire Main Cannon to destroy both wall 1 and wall 2 with 1 shot

Frame 36711 Fire Main Cannon at Becks Haus. Firing on this Frame prevents a 2nd Waltar from spawning as Iron Tank approaches wall 3, thus ensuring that the upcoming F item spawns properly and mitigating some Lag.

Frame 36890 Fire Main Cannon to destroy both wall 3 and wall 4 with 1 shot. This saves 18 Frames compared to using the Machine Gun to destroy wall 3 and wall 4.

Frame 36948 "I got a FVR! And the only prescription is more Iron Tank!"

Frame 37176 Fire Machine Gun at Foot Soldier to prevent Becks Haus from spawning with minimal Lag

Frame 37502 Turn here and allow the building to automatically correct Iron Tank's direction at X 139 on Frame 37531. This allows Iron Tank to miraculously move through the triple Becks Haus ambush while taking just 1 hit for 4 damage. This technique works on this Frame only.

Frame 37507 Delay 1 Frame to cause right Becks Haus to miss its first shot

Frame 37879 Turn to X 95 no sooner than here to manipulate Waltar to move closer to Iron Tank, thus opening an escape route

Frame 37978 Turn to X 108 no later than here to prevent a Becks Haus and a train from spawning for minimal Lag

Frame 37979 Fire Machine Gun at Waltar out of principle

Frame 39601 Rotate Main Cannon without delay in movement by pressing against the wall

Frame 39606 Fire Main Cannon at Hans to prevent some damage and Lag

Frame 39644 Turn left here at X 131 to cause the other Hans to miss its shots and to slip safely past Gustafu while leaving it alive

Frame 39729 Once safely clear of Gustafu, turn up and left toward X 204. 2 more Gustafu will shortly spawn. It is imperative that these 3 Gustafu remain alive until the next battery of Hans are reached, so as to prevent any other tanks from spawning for as long as possible. These 3 Gustafu will become trapped to some degree by the large trees and will generate approximately 34 Frames of Lag as they frantically attempt to engage Iron Tank, but this is still far less Lag than would be generated by the Waltars and Becks Haus that would spawn if these Gustafu were destroyed. Furthermore, the Gustafus' projectiles cannot penetrate the trees behind which they are trapped, which both keeps Iron Tank safe, and also mitigates Lag somewhat by greatly limiting the length of time that each Gustafu projectile is moving on the screen.

Frame 39916 Rotate Main Cannon to forward position to prevent 2 Frames of Lag (this is likely due to some slight AI manipulation of one of the 3 Gustafu on the screen)

Frame 40000 Because these 2 Hans are bypassed safely (purely by luck), and the Lag they cause is negligible, there is no need to destroy them. Furthermore, not destroying them also conserves Bullets and results in ideal spawns, which can be subsequently destroyed to mitigate even more Lag.

Frame 40190 Rotate Main Cannon here with no additional Lag

Frame 40241 Fire Main Cannon at Hans from maximum range for minimal Lag to mitigate Lag

Frame 40302 Fire Main Cannon at Becks Haus for minimal Lag to prevent ramming it

Frame 40303 Rotate Main Cannon here for minimal Lag

Frame 40302 Fire Main Cannon at Becks Haus for minimal Lag to mitigate Lag

Frame 40361 Rotate Main Cannon back to forward position here with no additional Lag

Frame 40566 Once clear of the mine, turn toward X 193 on earliest ideal Track Status to place Iron Tank in position to hit the first turret of Boss Headquarters fortress. Navigate those mines like a champ!

Frame 41206 Fire 1st shot at first turret of Boss headquarters fortress

Frame 41220 Fire 2nd shot at first turret of Boss headquarters fortress. This 2nd shot must be delayed after the 1st thus to prevent it interfering with the 1st shot.

Frame 42517 Last Frame of input

Noxxa: Judging.