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

Submission #6649: Zinfidel's PSX Armored Core in 28:04.38

Console: Sony PlayStation
Game name: Armored Core
Game version: USA v1.1
ROM filename: Armored Core (v1.1).bin
Branch:
Emulator: BizHawk 2.4
Movie length: 28:04.38
FrameCount: 99872
Re-record count: 22767
Author's real name: Zach Friedland
Author's nickname: Zinfidel
Submitter: Zinfidel
Submitted at: 2020-03-08 06:10:52
Text last edited at: 2020-05-07 10:23:43
Text last edited by: Spikestuff
Download: Download (58506 bytes)
Status: published
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Author's comments and explanations:
Armored Core sees the player take on the role of a Raven: a mercenary who customizes and pilots a giant mecha (an Armored Core) for powerful corporations in a dystopian future. In this TAS I disappoint the corporations by taking their money and failing to do nearly anything they ask of me so that I can destroy the super AI that has been pulling their strings the whole time.

Timelapsed Encode


(Link to video)
This encode timelapses through the mission aborting segments of the game since they are repetitive and boring. Commentary is included in the subtitles.

Unabridged Encode


(Link to video)
This encode is completely unedited aside from the title card and is close to what an official encode of the movie would be. Commentary is also included in the subtitles.
For Encoders: Here is a link for the SubRip format subtitles for the unabridged encode: https://pastebin.com/ZugvBZi4

Version Information

  • Emulator used: BizHawk 2.4
  • BIOS used: SCPH-5501 (ps-30a.bin)
  • Game used: SLUS-01323 (v1.1, NTSC-U)

Game Objectives

  • Genre: Simulation / Third-Person Shooter
  • Heavy glitch abuse
  • Fails missions to save time

Goal

Category

This run is for the any% category, which permits two major techniques: out-of-bounds clipping, and aborting missions. Almost the entire game is skipped as a result, and the few missions that have to be completed are mostly subverted by clipping through them.

TAS vs RTA, and World Records

The RTA timing for this TAS is 29.57:85, and the world record for this category is… 23.14:00. "Wait, what? Your TAS is slower than a normal speedrun?" is what you might want to ask me, and reasonably so.

The Armored Core speedrunning community (and many others) permits and encourages runners to use PlayStation 2 consoles, and more recently the PlayStation TV (PSTV) platform, to do their speedruns. This is because those platforms have significantly better disk load times than original PSX hardware, which BizHawk's Octoshock core emulates faithfully. For late-model PS2s using the FDL (fast disk load) option, load times in Armored Core are reduced by 40%[1] . The PSTV platform is even faster, reducing load times by about 65%[2].

Since the category of this speedrun means that most of the speedrun is spent loading and unloading missions, even with significantly faster per-mission completion times, it is much slower than runs using the PS2 or PSTV.

[1] Measurements based on: https://www.nicovideo.jp/watch/sm19696898
[2] Measurements based on: https://www.youtube.com/watch?v=546uoe_3poU

Glossary

  • AC: Armored Core - the name of the mechas that you pilot in the game.
  • MT: Muscle Tracer - the name of the simpler, non-customizable mechs that you fight throughout the game. "Muscle Tracer" is the name of the technology that interfaces pilots to mechas.
  • Raven - the name of a mercenary that pilots an AC. The player is a Raven.

Techniques Used

Aborting Missions

In Armored Core, the player does not "lose" or get a game-over screen when they fail a mission. The game simulates a world where many Ravens (pilots) are active and succeeding and failing. The player is not special in this regard, and the timeline of the game moves forward regardless of the outcome of an accepted mission.

This fact is abused by simply aborting missions the moment they are started rather than playing them. The game's timeline moves forward, the player is penalized for repairs and rearming (if necessary), and the player is able to select a new mission. There are 33 missions skipped in this fashion in this run.

Out-of-Bounds Clipping

Equipping a certain combination of parts, and then moving backward at a precise moment while strafing left or right will cause a glitch in the walking animation that causes the player to move through walls. This glitch will typically cause the player to fall right through the floor they are standing on and dumps them into the interstitial space of the map.

The player will regain control after this animation glitch plays out for a few seconds, then they are able to fly around. This allows the player to skip level design and go straight to mission triggers to complete levels very quickly. Some missions in this game can be completed in seconds without hardly moving at all using this technique.

Coordinates Over/Underflow

Armored Core's map coordinates are stored as signed 16-bit integers, which means that maps have limits at -32,768 and 32,767 for each axis. The player and other entities are typically prevented from ever getting close to these limits by in-game mission-failure boundaries, or just obstacles like walls, but if entities cross these boundaries, their position is either over- or under-flowed and the entity will be "teleported" to the other side of the map.

This property is used while clipping out-of-bounds by falling to the bottom of the map, causing the player to reappear at the top so that they can then land in some part of the map that is very high up. The most amusing and useful application of this property, however, is on the Destroy "Justice" mission, where the mission's target destructible can be destroyed from the opposite side of the map. See the mission notes for more information.

Laser Blade Damage Manipulation

Laser blades, equipped to the left arm of ACs, are very powerful melee weapons, capable of doing the most damage per hit of any weapon in the game.

The laser blades' damage ratings by themselves are high, but not actually that impressive on their own. Where their true power comes from is the damage multiplier they get when used in the air. Landing an aerial laser blade strike imparts a multiplier that is commonly between 4x to 6x the rated damage of the weapon, but can be as high as 16x! With more advanced laser blade weapons and multipliers in the 10s, a single hit is enough to destroy even enemy ACs.

The multiplier you get for a laser blade strike is determined by the player's approach speed, the angle of approach, and how "deep" the laser blade hits. It is not as simple as "go as fast as possible" or "hit as deep as possible", and the higher multipliers are very very picky about having the right combination. In this run, laser blade strikes are manipulated every time to get very high multipliers in order to destroy enemies after just a little softening up.

Mision Notes

0: Ravens' Test

The two Stork MTs in this stage can be a huge pain to deal with with the starter AC because they are very mobile, and very flighty, while the starter AC is slow and runs out of juice easily. So, getting the Storks close together and preventing them from flying away is of paramount importance.

The pathing used to boost to the first Stork causes the second Stork to jump down from its platform early on. The starter rifle's shots are timed to stun the first Stork right as it tries to fly away, and keeps it locked down until we can finish it off with the laser blade. Stork 2 is then nearby and easy to get to.

19: Destroy Plus Escapee

There is a brief pitstop in this level to collect the GBG-XR generator, which is one of the two best generators in the game. It is used later in the final build.

34: Destroy "Justice"

This mission is entirely subverted by abusing the property of the game that entity coordinates under/overflow when entities cross the limits of the map. Justice is a giant orbital laser cannon that the player is shuttled into in order to destroy it.

The map itself is a long tube, running to and from the absolute limits of the X-axis of the map space. The side the player starts in is open to space, and the very opposite side has a wall with Justice's power core, which must be destroyed to finish the mission. In between these two points are forcefields and hoards of enemies.

The WC-GN230 grenade launcher is equipped for this mission due to its huge blast radius. At the start of the mission, we turn around and face the open side of Justice, and get fairly close to the mission border. Then, we fire grenades into space. What happens here is that the grenade projectiles are entities themselves, and cross the map limits, teleporting to the other side. On the other side of the X-axis happens to be the wall that has Justice's power core on it!

The grenades explode on the wall, and their blast radius is large enough to damage the power core on the other side. Three grenades later and the mission is over, without ever actually advancing into the map.

35: Mop Up Chrome Remnants 2

We want to get to the 4th basement floor of this map as quickly as possible since entering the 4th basement floor triggers the radio transmission telling us to return to the surface. This radio transmission must be activated to spawn enemies into this map.

To get there quickly, we clip out of the hallway the player starts near and fly directly to the basement floor. Once we arrive, the radio transmission plays, and it is time to return to the surface.

The final mission trigger for this level is in the hallway the player starts near, so we need to arrive inside that hallway as quickly as possible. Here's where things get a little tricky: with the final build equipment we have on this mission, we don't have enough energy to fly in between all of the rooms in the complex into the hallway. What we can do, however, is position directly underneath one of the support columns in the second basement floor, and fly directly through it to the hallway.

The support columns in this map don't have collision planes on their tops or bottoms, so this effectively lets us clip into the room, without actually entering it. This shortcut gives us enough leeway to fly directly into the hallway trigger point.

Boss Savage is waiting for us outside, and he is quickly dispatched.

36: Destroy Floating Mines

This mission is split into two parts, which I will refer to as "The Melee" and "The Gauntlet."

In The Melee, we must fight through two rooms full of very tough enemies to get to the second part of the mission. In order for any of the enemies to spawn at all in this mission, the door to the first melee room must be opened. The enemies in this room do not need to be fought, however. So, we position our AC at this door, begin to clip through it, and as we pass through, open the door. This spawns the enemies in the room and the map, while we begin our descent to the second room of The Melee.

The second room melee must actually be fought, and the enemies appear once the second door is opened. This room is full of the titular floating mines, and they are used generously to end the fight as quickly as possible. For some reason, the mines' explosions do an extremely large amount of damage to enemies even though they don't do much damage to the player. For example, the Shinonome MTs have 10,000 HP, but getting hit by two mine explosions can bring them down to less than 1000 HP.

Once The Melee is done with, we move on to The Gauntlet. This is where the player would have to suffer through a very difficult, long level that includes two copies of the #1 Raven in the game trying to kill them, as well as a smattering of strong MTs. Instead of dealing with all of that, we just clip through the floor at the start of the mission, fall to the bottom of the map, wrap around to the top, and fall into the room housing the CPU of Hustler One - the secret AI antagonist of the game. Destroying this CPU finishes the game.

Mission Completion Times

Mission This TAS WR RTA[1]
Ravens' Test 00:13.50 00:38.00
Destroy "Justice" 00:11.50 00:20.00
Mop Up Chrome Remnants 2 00:58.50 01:37.00
Destroy Floating Mines Part 1 00:42.50 01:15.00
Destroy Floating Mines Part 2 00:22.00 00:36.00

[1] NTSC any% RTA on PSTV: https://www.youtube.com/watch?v=EicH8VtvAQg

Suggested Screenshots

Frame 3746 Frame 8528
Frame 87502 Frame 91875


feos: Really nice movie, even though it's not as entertaining as this game would allow if all levels were played for real. Gameplay segments in RTA are *way* longer than in this movie, and gameplay is all we care about, so this run is really solid. But since most of it is skipping missions, it has to go to Vault. Aborting missions is okay, since it's a normal feature in this game (the manual mentions it as one). Accepting.

Dacicus: Processing...

Spikestuff: If anyone wants to dump this in the future use 2.2.2 as 2.3 to 2.4 can crash when dumping.