Tool-assisted game movies
When human skills are just not enough

Submission #4885: Zakky the Goatragon's NES The Guardian Legend in 42:38.15

Console: Nintendo Entertainment System
Game name: The Guardian Legend
Game version: USA
ROM filename: Guardian Legend, The (U)
Emulator: FCEUX 2.2.2
Movie length: 42:38.15
FrameCount: 153742
Re-record count: 14727
Author's real name: Z.S.
Author's nickname: Zakky the Goatragon
Submitter: ZakkyDraggy
Submitted at: 2015-10-19 06:29:30
Text last edited at: 2015-10-22 14:24:47
Text last edited by: Spikestuff
Download: Download (29027 bytes)
Status: published
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Author's comments and explanations:
The Guardian Legend has always been a favorite of mine. I put this together as a fun project to see just how fast this game could be completed with precision not possible in real-time. I don't know that I succeeded, but hopefully, if nothing else, this might lay the foundation for future TAS work on the game.

(Link to video)


Shot Limit

There are four slots that are shared by the regular gun and subweapons. When a subweapon is equipped, it occupies 1-2 slots (depending on the subweapon) even if it is not being fired.

No subweapon equipped = 4 gun shots Saber Laser (uses 1 slot) = 3 gun shots Cutter Saber (uses 2 slots) = 2 gun shots

Once the maximum number of shots are on screen, no more shots can be fired until after the shot has disappeared from the screen or inflicted damage on an enemy (2 frames). On minibosses and bosses, shots have an explosion animation and no more shots may be fired until that animation has completed (26 frames).

Subweapon Damage on Minibosses/Bosses

Subweapons only do damage once every 8 frames to bosses. This appears to be based upon a global timer, as it is not based upon when the weapon first fires or hits. There is also a damage cap of 5.


The Guardian can not die unless she is at 0 health. So as long as her health is above 0, even if a hit does more damage to her than the amount of health she has, it will always just bring her health to 0. The Guardian’s hitbox is significantly reduced when she is at 0 health, also.

Invincibility Frames

After taking a hit or during a health restore the Guardian is immune to damage for a short period of time.

Damage invincibility frames appear to work like this:

  • If Damage Taken >= 15, Invincibility Frames = Damage Taken
  • If Damage Taken < 15, Invincibility Frames = 15

If a hit is taken that does more damage than the current health, damage taken counts as that current amount of health (Example: current health is 16, hit normally does 64 damage, damage taken = 16).

For health restore frames, Invincibility Frames = Health Restored

If a pick-up restores an amount of health more than what is needed to reach the current max health, only the exact amount of health taken to reach that current max counts as the health restored (Example: max health is 64, current health is 56, health restore normally restores 40, health restore = 8).

For any health restore and for damage taken that is greater than 15 it is possible to add an additional 15 invincibility frames to by taking a hit on the last frame of the initial invincibility, as the game does not assign damage during the taking damage animation.


Corridor Transformation Sequence Skip

Normally there is a short cut scene at the start and at the end of a corridor during which the Guardian transforms. This can be skipped by holding Select.

Hitbox Detection Cancelling

Whenever one of the Guardian’s attacks is within an enemy hitbox, the game does not check hit detection for that enemy. This prevents taking damage from the enemy itself if the Guardian’s hitbox is in contact with the enemy’s hitbox, but it also will prevent any of the Guardian’s other attacks from damaging the enemy. For example, if an enemy is taking damage from the Saber Laser, and the Saber is kept active while firing gun shots, the gun shots will pass right through the enemy.

Miniboss Room Quick Exit

After killing a miniboss, the game normally delays the exit from the room. However, there is a small window of time after the miniboss dies during which the item can be grabbed and the room exited without delay

Block Clip

After movement speed has increased (by collecting four defense ups), it is possible to clip through a single column of red pyramids (this also works on green miniboss room pyramids) by walking horizontally against the column for one frame and diagonally up and in that same direction for one frame.

General Notes

  • Only Corridors 1-10 and 21 are required to complete the game, so 11-20 are skipped.

  • A combination of Saber Laser and gun shots are used to take down minibosses and bosses. The Saber does the bulk of the damage and is supplemented by the gun shots. The Saber is kept active on all non-gun shot frames if hitbox cancellation is needed.

  • I used death warps after Corridors 2, 4, 5, 9, 10, and after the minibosses in 3 and 7.

Area and Corridor Notes


Corridor 0

I went with targeting only the orange diamond and red ship enemies here, being careful not to shoot anything else in the process.

Boss: The Defense System

I planned this out pretty extensively, noting down the intervals for the batteries and turrets so I could formulate a good flight path and attack pattern. It resulted in the defense system being mercilessly smashed.


Picked up the Saber Laser and a Red Lander.

Corridor 1

All the required corridors have a special task you need to perform in order to open the gates. For Corridor 1, it's to fire at the gate. I kept the Saber Laser active while firing the gun, as this was the fastest way I found to open the gate.

Once in the corridor I picked out the fish and sea horses for destruction. Later on I killed the last red eye as the additional squids it spawns caused lag if I didn't.

Boss: Blue Fleepa

Saber/Gun combination takes it down fast.


Miniboss: Blue Crab

This guy drops an attack up when killed, which increases gun damage by one and Saber damage by 2, essentially doubling damage output, so I stopped in to kill him. I was able to get a convenient spawn for setting up the quick exit without manipulation and the Saber/Gun combo made quick work of him.

On the way to Corridor 2 I stopped at a shop along the way to open the gate for Corridor 4. Yes, Corridor 4. To open the gate for Corridor for you need to enter and exit a shop until the shopkeeper opens the gate for you. The "intended" shop is the one across from the Corridor 4 entry room, but any shop will work, so it's faster to open the gate in Area 2.

Corridor 2

Touching the circuits opens the gate here. I just clipped the edges of each circuit's hitbox to get the gate open as fast as possible.

As for the corridor, I targeted the fish and seahorses and danced with some sea snakes.

Boss: Crawdaddy

The usual Saber/Gun combo. I reduce my health to 0 before canceling the hit detection, for the first death warp.


Corridor 3

Waiting in the room opens the gate. I used the time to run a few laps around the room.

I targeted the mushrooms here. Not much else of note here until the boss.

Boss: Blue Optomon

This was another boss fight I enjoyed working on very much. It was challenging to make sure that I was able to hit each shot at the earliest moment possible, while keeping up with Optomon's movements.

I headed off a bit further into Area 3 to take on a miniboss for one of four defense ups that I will pick up. I delayed a frame upon exiting the Corridor room and then a frame at the start and at the end of the next three rooms. This was to manipulate the spawn location for the upcoming miniboss.

Miniboss: Green Flower

This fight was a tricky one due to how the movement pattern of the miniboss works. The first direction the miniboss moves is determined by where the Guardian is standing when it begins fading in. From then on it will start bouncing at her. If it hits her it will move in the opposite direction it was just moving in. There are also a few frames after it hits during which it will not change direction if it hits again.

I was unable to manipulate a spawn closer to where the drop spawns once the miniboss dies, but with some careful movements and taking advantage of the hit detection cancel I was able to make this spawn work just as well. I also made sure to reduce my health to 0 for the death warp.


I grabbed the Cutter Saber and switched to the Saber Laser right before entering the next screen. This was to manipulate the enemy spawns to avoid taking damage, as it would put me below the amount of health I need for the upcoming miniboss fight.

Miniboss: Blue Flower

Stopped to kill this miniboss for another attack up. Same deal as with the green flower as far as manipulating the movement here went.

Corridor 4

Killed the mushrooms again here and added the laser shooting scorpions to the hit list because it prevented lag.

Boss: Teramute

Used Saber/Gun combo and reduced health to 0 for the death warp. Even with the most optimal rate of damage I fall an agonizing 15 damage short of a two-cycle.

I switched to the Saber immediately upon the continue as I need it equipped for later and it saves a frame exiting the room.


Miniboss: Crystal Star

This miniboss was much easier to manipulate the movement of than either of the two flowers. It dropped the second of the four defense power ups I needed to pick up.

Corridor 5

Shooting the "Corridor 5" sign will open the gate here. I decided to demonstrate how lenient the hitbox for that is.

I chose the cubes and volcanoes for destruction here.

Boss: Zibzub

I attempted to make this fight look interesting by causing Zibzub to bounce all over the screen. Unfortunately he was too fast for me to keep up with. The usual routine here.


Corridor 6

The entrance to this corridor is the only room I enter in Area 6. Firing a subweapon for a short duration opens the corridor gate here. Unlike most corridors the timer for this can be started before you have completed faded in, so I started firing the Saber off immediately.

I went after the cubes and volcanoes here again. It was very challenging to avoid both taking any damage during the corridor itself and preventing any lag.

Boss: Glider

The same old Saber/Gun routine. This fight comes close to a 1 cycle, but not as close as the Teramute fight came a 2-cycle as I was 24 health short here. I also found a weird “dead frame” where it seemed like the Saber should have done damage, but didn't. I would have needed


Corridor 7

Entering and exiting this room three times will open the gate here.

Started off the corridor here with some laser dodging, then destroyed the mushrooms (yes, mushrooms in an organic corridor), bubble shooting enemies, and the little green octopi that eat your weapons fire. Also, this is the only corridor I used the Cutter Saber in.

Boss: Eye Growth

The Cutter was used here for its wide horizontal range. Also the small eyeballs don't count as boss enemies, so the Cutter can do damage to them every frame.

After the corridor I proceeded further into the area to pick up the third and fourth defense ups. The fourth required me to fight a miniboss.

Miniboss: Red Crab

I originally switched the the Saber as you can fire 3 shots from the gun when it is equipped as opposed to only 2 shots when the Cutter is equipped. However, despite the fact it took more time to kill the miniboss, it was faster overall due to not having to enter the menu.

The death warp here was unique in that I set it up so that I could grab the item and take the death without even needing to exit the room. This took quite a few tries to set up and when I finally made it work, the fatal hit was set up to happen on the last possible frame it could!


Corridor 8

Another area I didn't visit beyond the corridor room. Opening this gate just requires the subweapon to be used when set to NO USE. The death warp set this up nicely as it automatically unequipped my subweapon.

As for the corridor itself I set out to destroy the mushrooms, small floating eyeballs, mantas, projectile eating octopi, and laser ships. I actually missed an eyeball, but didn't catch this until it was too late to fix it.

Boss: Red Grimgrin

There is a lot going on behind the scenes in this boss fight. It wasn't just a simple Saber/Gun combo and win fight like many of the early boss fights as Grimgrin had way more health than the chips for the subweapon use would hold out for. Instead of keeping the Saber active the whole time, I took damage from the eyeballs, trading 4 health for 15 frames of invincibility. This allowed me to let off the Saber during any frames it wasn't doing damage.

It also worked out that I was on a very favorable spot on the item drop table. I was able to pick up a heart to take some extra damage and then a red chip to restore my chips for more Saber use. My final drop was a blue chip which gave me just enough chips to finish off Grimgrin.


Headed straight through to Corridor 9. I tried to manipulate not taking any damage, as it cost me 2 frames to enter the corridor, thanks to the 0-health hitbox, but all the manipulations cost more than 2 frames.

Corridor 9

Walking over the gate opens the way here.

I avoided the red diamonds and blue ships during the corridor, but tried to kill everything else, especially the annoying seed pods.

Boss: Blue Eyegore

The lasers do 1 damage and grant 15 frames of invincibility. I took advantage of this to conserve chips and health. Toward the end I took damage from Eyegore himself to reduce my health to 0 for the death warp.


This section was all about optimizing the walk through the area. I used the block clip twice here.

Corridor 10

The requirement for opening this gate is to hold down the fire button. I decided to spin around while doing so, except thanks to the fact I had not picked up any Consecutive Fires to increase the default firing rate, the shots only fired in the same two directions. As soon as the gate opened, I ran off in the direction I was facing and "bounced" right off the wall and back over in time to enter the corridor.

The corridor itself was pretty much attempting to kill everything I could. It was all about lag reduction instead of lag prevention here.

Boss: Red Eyegore

Just did the same thing here as I did for the Blue Eyegore.


Corridor 21

This is one I could have ended up redoing many many times. I knew I was going to have to manipulate item drops in this corridor for the Blue Grimgrin fight. The question was where I needed the table to be and how I was going to get it to that point. Fortunately it only took one redo for me to figure out where the table needed to be at.

Blue Fleepa

I started out by destroying rocks to set up a health drop upon Fleepa's defeat for the ZibZub fight. The fight was the same as the first time, except Fleepa went down much faster.


I avoided destroying rocks because the next drop wasn't going to take long to prompt and I wanted it to happen after the Zibzub fight. The fight was the same as the first time, except I didn't move as much.

Blue Clawbot

I used damage to conserve my chips and then kept the saber active to avoid taking a fatal hit. The third drop, a blue chip, occurred during the fight, and I grabbed it to gain a few chips back. I went into the final phase with 0-health which allowed me to position perfectly between Clawbot and his laser's hitboxes, making his final attempts to kill me futile and allowing me to conserve chips. I received a nicely timed level up after the fight, allowing me to start the next fight with full health.

Red Optomon

I destroyed more rocks before this fight to prompt the next drop and then use the same strategy on Red Optomon that I used on the Blue Optomon earlier.

Blue Grimgrin

I prompt the next drop, a heart, and destroy a few more rocks to set me up for a red chip drop on this fight. I get the chip drop and it carries me through the rest of the fight. There were two further drops that occurred on this fight that despite not needing, I attempted to manipulate to drop where I could pick them up, and wasn't quite able to do.

Red Bombarder

A "recharge" fight, so to speak. I took damage from the Bombarder to preserve chips and used the "health restore invincibility" to do so as well.


This fight took a long time to complete. I had to deal with unavoidable lag, the massive amounts of health It had, and I had to redo half of the fight because of not so optimal gun usage. I also made it a point to take no damage in this fight, as that's pretty much impossible to do quickly in real time, if even possible at all.

Possible Improvements

Better labyrinth movement

I went over my movements very carefully in the labyrinths to make sure I did everything optimally, but that doesn't mean that I may not have overlooked something in the process.

Better Defense System and Eyeball Growth fights

I considered and plotted these very carefully, but I'm not willing to rule out a more optimal way of destroying these.

Better lag management

In most places I was able to avoid lag, but on Corridors 9, 10, and 21 and especially boss fights like Red Grimgrin, the Eyegores, the Corridor 21 refights, and It, it just wasn't a possibility. Not killing one enemy, firing off your gun or saber on the wrong frame, and so many other factors go into whether the lag will occur or not.

Better corridor flight

I tried my best to fill the downtime during the corridors. That definitely was not something I felt I was good at, so this might be a point of improvement as well.

Huge huge thanks to the following:

  • FatRatKnight, for all his work on this game and his hitbox script. I learned a lot from his posts in the forum topic and, uh, borrowed the script and used it extensively. Without that script I don't know that I'd have had the motivation to complete this project, assuming I'd have had the motivation to even start it to begin with!
  • The Admiral, whose stats and mechanics info I used extensively to determine my plans of attack on bosses.
  • Mattrick_, theseawolf1, ShinerCCC, Vaxherd, and any others from the TGL speedrunning community who I may have missed
  • Metasigma, Dragondarch, and all those whose interest in this project kept me motivated
  • And especially to all those who gave trying to TAS this game a go before me

Samsara: Added YouTube module, and judging.

Samsara: Ah yes, The Guardian Legend, an oft-requested TAS. Even if I'm not too familiar with the game, it's nice to finally see a legitimate full-game run making its way to the site.

This is a very solid run! I appreciated all the moments of entertainment scattered about the long wait times (and bonus points for lots of syncing to the music). It looked like everything was managed precisely, from reducing lag and quick boss/miniboss kills to item manipulation and health management for the death warps.

Excellent work all around! Accepting to Moons.

Spikestuff: I'll just publish this before I die to Chrono Trigger.

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