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Submission #4319: zk547's DS Metal Slug 7 in 21:17.65

Console: Nintendo DS
Game name: Metal Slug 7
Game version: USA
ROM filename: xpa-ms7u.nds
Branch:
Emulator: Desmume 0.9.8
Movie length: 21:17.65
FrameCount: 76437
Re-record count: 58000
Author's real name:
Author's nickname: zk547
Submitter: zk547
Submitted at: 2014-05-27 01:50:22
Text last edited at: 2014-06-08 05:35:35
Text last edited by: feos
Download: Download (24907 bytes)
Status: published
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Game objectives

  • Emulator used: Desmume 0.9.8 with Advanced Bus Timing ON
  • Aims for fastest time
  • Plays at Hardest difficulty
  • Does not abuse death or use continues

About this run

This TAS was initially started sometime in 2013, before Desmume 0.9.9 was released and when Desmume 0.9.8 was still the most recent version. Real life stuff and demotivating sections in the run made this run take a lot longer than it should have. Now in 2014, when Desmume 0.9.10 is now released, I finally finished this run.

This run uses Eri through all 7 missions without dying. Eri is chosen because of her ability to aim grenades in 8 different directions and receive twice the number of grenades from the bomb/grenade item. The extra grenades become useful throughout the run and make her a lot faster than the other characters, especially in the final mission. Despite not dying at all, this run still manages to beat mtvf1's Eri/Tarma run by 605 frames. For those wondering, this run beats mtvf1's Marco run by 6763 frames.

Weapon Damage Data

The information here has been analyzed by mtvf1, but for convenience, I'll include it here.
  • Pistol: 10
  • Melee attack (knife, kick): 30
  • Grenade: 100
  • H: 10
  • Big H: 15
  • 2H: 10 (fires two bullets at a time)
  • L: 8 per 2 frames (1 bullet consumed every 4 frames)
  • R: 30
  • D: 30 (Not used in the run)
  • I: 30
  • C: 30 (Though obtained, not used in the run)
  • G: 100
  • F: There are two parts: the "main" flame and the "side" flame. The "main" flame does 20 damage per 2 frames while the "side" flame does anywhere from 0-5 damage per 2 frames. The "side" flame damage depends on how much it covers the enemy. The "main" flame can hit an enemy a maximum of 13 times for a damage of 260. The total max damage you can do with F is 314.
  • S: 200
  • Big S: 300
  • T: 10 per 2 frames for however long the shot is hitting the enemy. (Not used in this run)
  • Z: This weapon can "hit" an enemy 3 times. Every hit does 100 damage. Max damage is 300. This weapon is also treated like a melee attack.
  • Firebomb: 80 (The smoke of the firebomb can do 15 damage to other enemies that are close to the intended target)
  • Slug Vulcan: 10
  • Slug Cannon: 200
  • Slug Attack: 400
  • "Gundam" (Slug Gigant in mission 6) Punch: 250
  • Gundam's Cannon: 10 per 2 frames for however long the shot is hitting the enemy.

Note: Some characters (Macro/Tarma) do extra damage with certain weapons (pistol/slug vulcan and cannon), but since Eri doesn't get any of those benefits, we don't need to worry about them.

Tricks

Turnaround Cancel:

While crouching, when you attack, you can immediately turn around and do something else. For certain weapons, you can immediately turn back around and attack again. This cancels the delay between time you fire a weapon once and the time you can fire again, allowing you to fire at a much faster rate. This can also be done with grenades and melee attacks. However, when doing this with melee attacks and Z, you must wait 2 frames before turning around to cancel the attack animation, but it is still faster than just crouching and attacking.

Super Change:

Discovered by mtvf1. When you change from a weapon to pistol or vice versa while standing, the gun sprite immediately changes rather than the long animation that happens when you change while crouching (Of course, you can use Turnaround Cancel to cancel this long animation). Because the gun sprite immediately changes, you can instantly fire again. Super change takes advantage of this by continuously changing your weapon, which continuously changes the gun sprite, which allows you to fire again instantly again and again.

For weapons like R, C, I, and G, you can fire a 2nd bullet earlier than normal by firing the 1st bullet, switching to pistol, switching back to the weapon and firing again (Of course, while you're in pistol mode, you can fire a shot before changing). For melee attacks, switching weapons cancels the attack animation, allowing you to attack again. In the case of grenades, switching weapons after throwing one grenades allows you to throw a 2nd one instantly. For weapons like S and F, you can use Super Change to fire pistol or throw grenades during the time you have to wait before you can fire another shot. It also allows you to fire S and F again a few frames earlier. While it is better to use Turnaround Cancel whenever possible, when jumping or walking towards an enemy, Super Change allows more damage output by allowing you to fire bullets faster and fire pistol shots/throw grenades in between the bullets.

Since Super Change takes advantage of the instant gun sprite change, it's best to use it when you only have 1 weapon (Or 1 weapon and 2H because 2H has a different gun sprite). Changing from one weapon to another doesn't work because nearly all weapons have the same gun sprite. The exceptions are when you switch from H or L: since they auto-fire multiple bullets at once, if you switch to another weapon, you can fire again instantly.

When using this to attack downwards, after switching you must wait 2 frames before attacking downward again.

Faster H/"Semi 2H":

Discovered by mtvf1. Although H already auto fires multiple bullets at a fast rate, it is actually possible to fire H at an even faster rate. This is done by pressing fire once (Y button by default), waiting 4 frames, pressing fire and down once, turnaround immediately, and firing again back in the original direction. By doing this, every other bullet that is fired will actually be two overlapping bullets, resulting in a faster H. This can also be done with Big H.

H Auto-fire Transfer:

This takes advantage of the auto-firing properties of H. If you obtain another weapon while in the middle of the 4 bullets that you normally fire with H, the bullets that aren't fired with H are fired with the new weapon at the speed of H bullets. This trick allows you to fire bullets at a faster rate than using Super Change, but since H is required and H is only obtained a few times in the run, it is not used often.

One-shot killing a shield soldier/"Piercing Bullet":

Sometimes when the screen is scrolling to the right/left, hitting a shield soldier at a certain time as he spawns on the screen will kill him instantly, rather than hitting his shield. I'm not sure how this happens exactly, but it is a useful trick nonetheless. This can sometimes save grenades and time by not having to use a grenade or knife to kill the shield soldier.

Other Things to Note

  • Most of the time, jumping is faster than walking. There are a few cases where walking is better than jumping
  • At the beginning of a mission, when you descend with a parachute (mission 1, 5, 6, 7), don’t jump right away. Instead, hold right for 2 frames before jumping. It is slightly faster. However, when you walk in from the left (mission 2, 3, 4), it’s best to jump right away.
  • Although Super Change allows you to attack faster, changing your weapon sometimes causes lag, which costs frames. Therefore, it is best not to use it when not using it doesn't cost any time.
  • When using the gundam, it's best to walk 14 frames (sometimes could be more due to lag) before jumping except at the end.

Stage by stage comments

Since mtvf1's Eri/Tarma run is nearly 2 minutes faster than mtvf1's Marco, I'll be comparing my run with his Eri/Tarma run

Intro: 7 frames lost / 7 frames behind

7 frames were lost, most likely from using a different emulator.

Mission 1:

Part 1: 83 frames saved / 76 frames ahead

Using the "Piercing Bullet" to kill the shield soldier at the beginning of the mission allowed me to destroy the 1st gun turret faster while continuously moving toward the right. At the 2nd and 3rd turrets, if you destroy the two turrets and kill the two soldiers that come from the left fast enough, the screen will scroll to the right a lot earlier, allowing you to move on to the next section a lot earlier.

Part 2: 20 frames saved / 96 frames ahead

Time was saved here from more optimized strategies.

Part 3: 18 frames saved / 114 frames ahead

Time was saved here from more optimized strategies and having less bullets on screen for less lag.

Boss: 48 frames saved / 162 frames ahead

58 frames were saved from using a new strategy against the boss. Rather than having the boss appear at the top and then using falling soldiers to do double/triple damage with cannons like mtvf1 did, I instead have it cycle around me twice and time my cannons so that I can damage two parts with one cannon. 10 frames were lost from the prisoner tally up by having 2 more prisoners than mtvf1.

Mission 2:

2 frames were lost in the transition for an unknown reason, despite pressing Start at the right time to completely skip the cutscene.

Part 1: 65 frames saved / 225 frames ahead

Time was saved here from more optimized strategies.

Part 2: 64 frames saved / 289 frames ahead

Picking up firebombs costs 4 frames, but they help save time later in the mission. More time was saved from better optimizations.

Part 3: 35 frames saved / 324 frames ahead

Time was saved here from more optimized strategies.

Boss: 39 frames saved / 363 frames ahead

40 frames were saved from using leftover firebombs against the boss along with vulcan and cannon. 1 frame was lost from the prisoner tally up for an unknown reason.

Mission 3:

6 frames were lost in the transition for an unknown reason.

Part 1: 43 frames lost / 314 frames ahead

43 frames were lost from saving 3 grenades. Since I'm not going to die, it's important to save some grenades for later in the mission.

Part 2: 47 frames saved / 347 frames ahead

Using H Auto-fire Transfer here allows me to fire R at the speed of H, which allows me to destroy enemies faster. Because of this, I manage to save time despite using 1 less grenade

Part 3: 0 frames saved / 347 frames ahead

Nothing much to say here since this part is a semi-auto-scroller and mtvf1 did this part as fast as possible already.

Boss: 85 frames saved / 432 frames ahead

103 frames were saved from a better strategy against the boss. When the cannon head appears in the leg part of the boss, Z can do 400 or 500 damage. So I attacked the legs at the beginning to spawn the cannon head as soon as possible and then started attacking the top part while waiting for the cannon head to appear. 18 frames were lost from the prisoner tally up by having 3 more prisoners

Mission 4:

0 frames were lost/gained in the transition.

Part 1: 25 frames saved / 457 frames ahead

Using Super Change allows me to destroy the helicopters faster at the beginning. Taking the S costs about 230 frames, but since this is hard mode, I don't have enough grenades to skip S (The tank right in front of S has 1100 hp, which would deplete my grenades drastically). Using 4 grenades and H to destroy the last helicopter is faster than trying to use S by a little more than 10 frames.

Part 2: 8 frames lost / 449 frames ahead

At some sections, the screen scrolls at a random time, so I tried to manipulate the screen to scroll as early as possible. Using S caused a lot of lag, but if I didn't use S, I would lose even more time. At the section where you have to destroy the truck and the tank, using just S to destroy them is fine as long as you destroy them fast enough. Using grenades doesn't make the screen scroll earlier. Altogether, this was a frustrating section that halted progress for a while. In the end, I was pretty satisfied with losing just 8 frames and decided to move on.

Part 3: 51 frames saved / 500 frames ahead

Using grenades at the beginning to destroy things faster helped save time at the beginning. In the middle where I fight the man-eater plants, I use just cannons to destroy them because using vulcan creates a lot of lag. Only once do I use vulcan because I have to save one cannon for later (Though I ended up not using the cannons because it turned out to be slower from lag).

Boss: 31 frames saved / 531 frames ahead

31 frames were saved in the boss battle. mtvf1 threw grenades while using Z, which is slower. Instead, I use all of Z before switching to F and using grenades. While using F, I only fire when I am able to get 13 hits for a base 260 damage. 0 frames were lost/gained in the prisoner tally up because I had the same number of prisoners as mtvf1.

Mission 5:

3 frames were lost in the transition for an unknown reason

Part 1: 3 frames saved / 531 frames ahead

Not much to say here either. mtvf1 had already optimized this part well. There is only part where I saved frames which was at the beginning, where I optimized the turnaround.

Part 2: 46 frames saved / 577 frames ahead

Better optimizations led to time being saved here. I had to use a grenade to kill the soldier that came out of the destroyed tank because I couldn't shoot him with pistol for some reason.

Part 3: 146 frames saved / 723 frames ahead

This is where Eri's ability to aim grenades truly shines. Unlike mtvf1, I picked up extra grenades from one prisoner, which allowed me to use them to "snipe" soldiers that can't be killed fast enough with pistol or big S, saving a lot of time. At the helicopter fight, I was able to somehow skip fighting the rest of the soldiers and move on a lot earlier than mtvf1. It is also faster to walk and jump underneath the arches rather than continuously jumping and going on the top.

Part 4: 39 frames saved / 762 frames ahead

Using grenades to destroy one of the energy balls at the beginning saved a few frames because I could use big S earlier to destroy the remaining two energy balls. At the part where you destroy two tanks, the screen scrolls at a random time, so it must be manipulated.

Boss: 29 frames saved / 791 frames ahead

29 frames were saved from the boss battle. I waited a little to destroy the bottom two parts together at nearly the same time, which caused less lag than there would have been if I had destroyed each part at separate times. I thought having 10 grenades would save time, but it turned out to lose/gain 0 frames as just having 7 grenades. Maybe it's because the third big S shot can hit the top part at the same time as the 10th grenade. In this run, I opted for using all of my grenades. While I saved one prisoner in part 3, I managed to avoid one prisoner mtvf1 didn't avoid, so I didn't lose any frames at the prisoner tally up.

Mission 6:

4 frames were lost in the transition for an unknown reason

Part 1: 77 frames saved / 864 frames ahead

This is where the run starts to differ from mtvf1's run. At the beginning I optimized the fight against the two cars/trucks, destroying them faster while still saving grenades (though I used more R). The two helicopters afterward can be destroyed faster, but the soldiers that come out in the right come out at specific times so there is no advantage to using more grenades than necessary. Unlike mtvf1, I had to pick up firebombs because I didn't have enough grenades and R to get through the rest of the section fast enough. I lose time from having to use firebombs, but gain more time from not dying twice. The two helicopters at the end can also be destroyed faster, but like earlier, the soldiers that come out in the right come out at specific times so there is no advantage to using more firebombs or G than necessary.

Part 2: 107 frames saved / 971 frames ahead

I saved enough G from part 1 to skip the S. Because I only have G, I can also use Super Change more effectively. If you destroy the first helicopter fast enough, the screen will scroll before spawning extra soldiers.

Part 3: 65 frames saved / 1036 frames ahead

Even though I lost a few frames against the helicopters because I had to use firebombs, I saved time from not dying again.

Part 4 (gundam action): 13 frames saved / 1046 frames ahead

Another frustrating part where lag would cause me to lose frames. I tried to use vulcan sparingly. It is better to shoot the soldiers rather than stepping on them because it causes less lag. At the end, you have to reach a certain point before the screen starts scrolling so it is best to walk a little and jump to that point. This is also the largest margin of total frames saved compared to mtvf1's run before I start losing frames.

Boss (gundam fight): 484 frames lost / 562 frames ahead

This was another frustrating section that halted progress for a while. First, Allen can only be damaged once every 4 frames (discovered by mtvf1) so if you use vulcan while moving toward him, some of the bullets will not do any damage. Second, because I'm not using Tarma, I don't do extra damage with vulcan and can't use vulcan fix. This becomes problematic because pressing Y at certain times changes the RNG and the next thing Allen does. So manipulating Allen to just stand there was lot harder with Eri because I had to time both the Y (vulcan) and A (cannon) buttons unlike Tarma, who can just hold Y and time pressing A. Although using the Gundam Punch does 250 damage to Allen, it also makes him invincible for a long time so it's only used at the end as a finisher. 466 frames were lost from not being Tarma in the boss battle. 18 frames were lost in the prisoner tally up by having 3 more prisoners.

Mission 7:

1 frame was lost in the transition for an unknown reason

Part 1: 312 frames saved / 855 frames ahead

Although it looks silly, riding along the ground with the Slug Flyer is faster because it advances your X position by an alternating 4 and 5 rather than by just 4 if you stay in the air. Crashing the slug flyer at moment I did in the run makes the screen scroll almost immediately and skips any soldiers you would normally have to fight. I could crash it earlier, but crashing later was actually faster. I stayed at the top of the screen to eliminate the time Eri takes to ascend before descending. This saved about 440 frames, but I lost more than 100 frames from saving 4 grenades at the end.

Part 2: 119 frames lost / 736 frames ahead

Here, you can see the "semi big 2H" trick being put to good use here. When fighting the second tank, don't advance up to the tank because it causes a 2nd robot to spawn. Instead, keep your distance and use "semi big 2H" to destroy it from afar. Then the screen will scroll without requiring you to destroy the 1st robot that was initially there. You can also throw grenades, but since I have to save them, I only throw 1 to damage the tank and destroy the force field of one the futuristic soldiers that started leaping towards me. Later on, I obtain L and keep it all the way to the first boss, "shuffling" 3 weapons all the way there. I actually managed to save about 30 frames in the area right before the first boss, but saving 16 grenades cost me more time in the end.

First Boss: 116 frames lost / 620 frames ahead

Unlike mtvf1, I have to save all my Z for the final boss, so I only use L, S, grenades, and pistol to fight the first boss. This results in a slower boss fight that loses 116 frames.

Part 3: 19 frames saved / 639 frames ahead

Sometimes walking instead of jumping can save time. At the beginning when I get more grenades and S, by walking a little and then jumping, I am able to save 25 frames. Unfortunately, I lost 20 frames at the part I have to destroy the beam. Perhaps it’s from lag, but I tried my best to reduce the number of frames lost. In my first attempt at this part, I lost around 40 frames. Moving on, mtvf1 found a way to jump through the falling structure earlier rather than waiting for it to fall completely, which saved about 22 frames (originally I thought it saved 14 from early testing). However, a little after that, I actually have to walk a few frames to avoid jumping on the small slopes, which would be slower. Doing that caused me to lose 8 frames.

Final Boss: 36 frames saved / 675 frames ahead

46 frames were lost while fighting the tentacles from not dying for more grenades. The S and Z can hit multiple parts to do double or even triple damage. Despite this, having extra grenades can save time, but there is a limit to how many grenades I can save from the mission without losing too much time. 122 frames were saved from a new strategy against the head of the final boss. Instead of having it dive into the lava like mtvf1 did, I had it only come down halfway and shoot a missile diagonally. The advantage of doing that is that you can stay underneath the boss the whole time and continuously use Super Change to throw grenades at it. 40 frames were lost at the prisoner tally up from having 7 more prisoners than mtvf1.

Mission All Over! : 70 frames lost / 605 frames ahead

4 frames were lost for an unknown reason during the transition. 66 frames were lost in the final tally up from entering a different name. Not much to say about that.

Final Stats:

Continue: 0

Recaptured Prisoners: 25

Score: 2598490

In game Time: 14:53

Possible Improvements

  • It was originally believed that it wasn't possible to use Super Change when attacking downwards. However, I discovered that you can still use a sub-optimal version of Super Change when attacking downward. The catch is that you have wait 2 frames before attacking. This wasn't fully realized till mission 6 when I fought the two trucks/cars. As such, the boss fight in mission 4 can be improved by utilizing this to throw grenades downward faster.
  • Lag can probably be managed better to lose less time.
  • In mission 7, I had 5 S leftover at the end of the mission. In a future TAS, more S should be used earlier in the mission to lose less time.
  • The final boss could also be improved slightly by saving 2 more grenades. This could probably come from using the S that was leftover from the mission.

Thanks

  • Many thanks to mtvf1 for his Macro TAS and Eri/Tarma TAS, suggestions on improving my TAS, giving important RAM addresses, and information/discoveries on the Metal Slug series.
  • Anyone who followed the discussion on the forum and followed my WIP's


feos: Judging...

FractalFusion: Changed rerecord count to 58000, as explained by this post.

feos: Accepting as an improvement to both published branches, because this run fulfills "deathless" and "fastest" objectives, while being faster than both of those runs. Back when they were published separately, it was believed that the 2 objectives can't be met at the same time. Now they are.

Publishing...


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