Submission #7167: Drakodan's GBA Astro Boy: Omega Factor in 22:57.54

Astro Boy: Omega Factor is part of a long list of acclaimed Treasure titles, and like its brethren, it is a 2D side-scrolling beat-em-up. The game is structured in three main "legs": A first playthrough titled "Birth", a second Newgame+ playthrough titled "Rebirth", and a postgame cleanup event that unlocks the true ending of the game.

The aim of this movie is to finish the "Birth" playthrough as fast as possible and reach the first credits sequence; this is the most popular category in RTA at the time of writing, and is commonly accepted as the game's "Any%" category. Using the same movie file to progress onto a True Ending TAS is possible, but the upgrade route used in this movie may prove sub-optimal once gameplay restarts in the Rebirth segment.

Suggested screenshots: Frame 15345, Frame 28667, Frame 36372, Frame 38582, Frame 51777

Movie length: 82,277 frames

Re-record count: 30,611

As the game is a beat-em-up, the player has a variety of tools at their disposal to use in combat. Astro's various abilities are as follows:

Movement: Performed with Up/Down/Left/Right, as standard. Running speed is fixed in this game, and is very often the sub-optimal way to progress through the game.

Boost: Performed with either a double input on a given direction, a double-A input whilst grounded, or a singular A input in conjunction with a direction whilst airborne. This is the primary form of movement used in the movie, as boost speed is much higher than running speed, and has a couple of unique properties, including temporary intangibility allowing Astro to ignore projectiles and enemy hitboxes. Boosts can only be used consecutively whilst grounded, unless this stat is upgraded; whilst airborne, Astro will be unable to boost consecutively until becoming grounded, which is the condition for refreshing his boost.

Punch: The basic combat option, performed with B. Up to four B inputs can be used in succession to perform a punch combo, the fourth hit of which is performed as a kick.

Kick: The ending hit of a four-punch combo, can alternatively be used by pressing B whilst holding Down. The main utility of this attack is to extend combos by forcing enemies to enter a "Tumbling" animation; when regular enemies are hit by a kick, they enter a vulnerable state during which they travel across the screen and act as projectiles that can be used to damage other enemies in their path.

Finger Laser: Performed by pressing B whilst holding Up. This attack crosses the entire width of the screen, making it a valuable option when enemies are located on both sides of the screen. It is also the only form of regular attack the player has access to in any autoscroller segment, as hand-to-hand options cannot be used in these segments.

Super Meter: Used as ammunition for Astro's Super attacks. The number available is displayed in the center-top of the screen, and the meter is built by inflicting damage to enemies. It is important to note that triggering the Super attacks listed below incurs a 2~ second timeloss each time due to the startup animation they play. This timeloss is compounded if the game is experiencing slowdown whilst the startup animation plays, and so Super attacks are only used when they save more time than they would otherwise cost to use.

Machine Gun: The first of Astro's Super attacks, performed with L. This attack inflicts negligible damage, but covers the entire screen, deletes many projectiles and stuns all enemies that are hit. Stun time is increased the more this stat is leveled up. This attack is used very often in RTA runs to mitigate the presence of RNG, but is not used at all in this movie.

Arm Cannon: The second of Astro's Super attacks, performed with R. An augmented finger laser that lasts much longer and hits a wider area, this is the primary form of attack to dispatch Bosses and other enemies with very high health pools, as the damage-per-second is much higher than any other option the player has access to.

EX Dash: The third of Astro's Super attacks, performed with a simultaneous A+B input on the same frame. This attack acts as an additional boost which also damages all enemies in Astro's path and forces them into the Tumbling animation. A valuable option in some cases during RTA runs when the player does not have enough boosts to reach an enemy or platform, but is not used in this movie.

The stat progression system plays a large part in how quickly the player is able to progress, and how powerful their toolkit is. Astro gains upgrade points by meeting characters and understanding their emotions, which is logged in the Omega Factor. Every time a character is fully understood in the Omega Factor, designated by that character having a coloured portrait, Astro gains one upgrade point to allocate. Astro's stats are as follows:

LIFE: Increases Astro's Max HP by 10,000 per point. Starting value is 30,000, maximum value is 100,000. This stat is only boosted at the end of the movie file as it is the fastest stat to allocate points to by that time, and no other stats are relevant at that time. Otherwise, not enough damage is taken to warrant boosting this stat.

PUNCH: Increases the power of Astro's hand-to-hand attacks, this also includes the kick. This stat is boosted in the second half of the movie after maximising the primary attack stat as it costs very few frames to allocate points to, and a large number of points eventually alters the number of hits required to defeat regular enemies, as well as making a marginal difference on some boss fights.

LASER: Increases the power of Astro's Finger Laser and Arm Cannon, this is the primary stat for the movie, and for RTA runs. The amount of damage inflicted by the Arm Cannon is far beyond any other option in the game, and the various autoscroller segments force the player to use the Finger Laser, making this the only logical option as the player would otherwise have very low firepower during these segments.

SHOT: Increases the power of Astro's Machine Gun, as well as the stun duration. This stat is boosted in the second half of RTA runs, but is not used in the movie. The utility of this ability in RTA to mitigate RNG by forcing bosses into a stunlock is invaluable, but no bosses require this in a TAS.

JETS: Increases the number of boosts that Astro can use without landing by one, per point. Not used in the movie as repeatedly boosting whilst airborne only has niche utility which is further mitigated by each boost having a several-frame startup animation, and boosts can be used infinitely whilst grounded without investing points into this stat.

SENSOR: Improves Astro's ability to perceive his surroundings, such as night-vision, de-fog vision, and ability to sense when an undiscovered character is nearby. This stat is necessary to achieve the true ending of the game as it is required for a storyline event, but is not taken in the movie as it does not assist in completing the objective of reaching the first credits sequence.

The game has three difficulties to choose from upon file creation: Easy, Normal and Hard. This movie plays the game on Easy difficulty, as this is the current standard in RTA runs, and the differences between difficulties are not as substantial as commentors have claimed in the past, at least not in a qualitative sense. The biggest difference between difficulty levels is the number of Super attacks the player can hold in reserve; 99 on Easy, 5 on Normal, 3 on Hard. As Super attacks are in short supply on the harder difficulties, boss fights become a protracted, tedious affair as risk of dying isn't present, and the movie becomes much slower as a result. The player is also incentivized to collect as many upgrade points as possible on these harder difficulties to mitigate the relative loss in power, slowing the game down further. Whilst generally true and requiring creative solutions in many titles, I do not agree with the notion that a harder-difficulty run makes for a better movie in the case of this game.

Without exception, progressing through each stage is contingent on defeating enemy waves as fast as possible. At its core, this game is a series of enemy waves at various points of each stage, and progressing to the next wave is not possible until the current wave is defeated. The current wave being defeated is defined by all current enemy sprites leaving the screen entirely. This is the condition for the screen to unlock and continue scrolling through the stage until the next wave is reached, or for the next enemy wave within the same screen lock region to begin spawning.

When enemies are killed, they typically bounce across the screen before exiting the bottom of the screen. Punch/Kick/Finger Laser generally cause different enemy trajectories, and the same attack can cause different trajectories depending on frame data. For this reason, many enemy waves are not killed on the first possible frame, as the trajectory is not necessarily lower, and thus can result in a net timeloss.

The game features scripted upgrade points which are collected as a result of story progression, and optional upgrade points which are located by finding hidden characters in the stages. In total, three optional upgrade points are collected: Alejo in Stage 1, Magma in Stage 2 and Fumoon in Stage 3. These points are collected both due to a combination of the time taken to obtain them being negligible, boosting the Laser stat as quickly as possible to kill bosses faster, and avoiding needing to collect slower optional upgrade points in order to maintain the same rate of stat upgrading. The route has changed in RTA runs over the years, and details of how much time each collected point saves will be given in the stage notes.

Input buffering: All of Astro's regular abilities can be buffered so that if they are performed early, they will automatically occur on the first actionable frame. This allows the player to string together perfect combos and boosts even in RTA play, and is used to move perfectly throughout the movie.

Input delay: Conversely, the player has the option to perform a combination "imperfectly" by waiting after the input buffer period has elapsed, causing actions to be spaced further apart than normal. This can be utilised to manipulate RNG, such as enemy placements where a perfect hit would cause an unfavourable enemy spawn, or to set up a further combo by moving onto a different enemy on the "first possible frame", where a perfectly-buffered combo would make the player reach their next objective too soon and lose time. Furthermore, an in-progress punch combo can be delayed for so long that the current attack animation fully ends, causing the combo to end. This can be utilised to perform an "infinite" punch combo as enemies will remain in hitstun indefinitely and the punch combo will never resolve with a kick, preventing the enemies from entering the tumbling animation or being launched across the screen.

Combo-reset boost: An alternative method of extending a punch combo; a boost can be buffered after the third punch of a combo, after which a new punch combination can be buffered. As long as Astro is grounded and therefore getting his boost refreshed as soon as the boost animation ends, this can be performed indefinitely.

Boost cancel: When Astro performs a boost, he will travel in a straight path until the boost naturally runs its course. The player can cause a boost to end early by executing any of Astro's other abilities, or alternatively without using any abilities by pressing A. This is used extensively through the run for positioning, to set up combos, to avoid damage, etc.

Slope boosting: When moving up a slope, it is faster to boost horizontally into the slope that it is to boost diagonally and move parallel to the sloped surface. The game will simply push Astro upwards as needed, and more pixels per frame are covered with a horizonal boost than a diagonal boost.

Object clipping: Whilst boosting, Astro is not considered a solid object and is invulnerable to harm. This can be used to pass through enemies directly, and is very often used to displace enemies or be clipped short distances; when Astro finishes the boost animation and becomes solid again, he cannot occupy the same space as another solid object such as an enemy. In these cases, the game will force Astro to the nearest open space, on the side of the enemy which is closest. If Astro is against the side of the screen, the game will force the enemy to move inwards instead. This is exploited often to set up screen-wide attacks.

Camera scrolling: Related to game progression mechanics. Since the nature of the game involves getting enemies offscreen as soon as possible to progress, this can be further achieved by jumping in order to scroll the camera upwards, as most enemies exit the bottom of the screen. In many cases, this causes the screen to unlock after a wave at least several frames sooner, and is used on the majority of enemy waves in the game.

Lag reduction: This game is unfortunately prone to slowdown when too many sprites are onscreen at once. As such, certain actions are not performed on the first possible frame, as the resulting number of lag frames can result in a net timeloss. Lag can also be caused by specific boss actions/animations, so these are avoided where possible.

RNG manipulation: I am not certain about all of the variables that alter RNG in this game, but one element which is easily controlled is the frames which particle effects are generated on; these do advance the RNG, and so delaying attacks by a variable number of frames can control everything from enemy spawn positions to other RNG calls such as the car placements in 1-2 and general boss behaviour.

Included at the end of this section will be the listed ingame time value displayed in the bottom-right of the screen, for each stage segment. This metric is not used in RTA runs as it does not progress during Super attack startup animations, and so IGT optimisation would abuse Super attacks at every opportunity for maximum damage-per-second, at the cost of realtime. Nonetheless, it is a valuable metric when Super attacks are being used minimally as is the case in this movie, and a comparison shall be listed for each level segment between the time achieved in the TAS VS the time achieved in my RTA PB, which at the time of submission is the world record.

A very basic segment that serves as an introduction to the game, but RNG comes into play as early as the second wave, during which enemies can spawn at any part of the top of the screen. Camera scrolling is not practical when already airborne and without a boost to use, so these enemies are defeated as early as possible.

The first upgrade point is collected here, and the first instance of maintaining an RNG value from an earlier point in the run; the traffic light enemy only has time to spawn one car, but this car can randomly travel across the middle or bottom of the screen. If it moves along the bottom of the screen, there is no way to avoid either taking damage, or wasting time to move in order to avoid taking damage. Thus, RNG is manipulated here to have the car take the higher path. This is basically a 50/50 coin flip in RTA play. The first upgrade is put into the Laser stat, which will be boosted with every subsequent upgrade point until the stat is maxed, as this results in the largest net timesave over the game due to the amount of time spent in autoscroller sections, and the DPS that can be achieved against bosses with the Arm Cannon, even with the 2~ second timeloss per use from the startup animation.

Many enemy waves in this stage segment utilise the Machine Gun in RTA play as enemies tend to become scattered around the screen and are weak enough to kill in one hit, but this movie manages to cluster them in one place and kill the full wave(s) as quickly as possible without Super use, saving a great deal of realtime.

A very short movement-based section during which object clipping is used to a great extent; several boosts are ended early whilst inside an enemy hitbox so as to get clipped sideways and gain a more favourable position to begin the next boost from. No combat is necessary to clear this room.

Enemies in this room spawn at one of three points: left, right and top. I tested this room several times and was not able to come up with a faster kill/attack order than used in this movie. A specific number of spiders must be killed before the miniboss will spawn, so it is not favourable to stay in one location and wait for extra spawns. Rather, I start at the left side and move into range to kill enemies from the other spawn locations as soon as possible. Rooms such as this one are one of the reasons that the old RTA upgrade route was to put the first upgrade point from Alejo into Jets, as it makes this room easier to manage and would absolutely result in this isolated room being faster, but would result in a net timeloss across the entire run.

Not the most exciting fight, but buffering an Arm Cannon on the same frame as a punch landing as soon as the boss is vulnerable four times is absolutely the fastest way this fight can be finished, even after the startup animation. I tested every other method including using combo-resets, and every other method loses varying numbers of frames. This is also the method currently used in RTA runs.

Using frame-perfect boost cancels after the boss dies saves no time, but it's fun.

The first autoscroller segment, and the first time I take great lengths to make what I'm doing more entertaining, as these segments are painfully boring if the bare minimum is done to progress. Any time I'm not required to be attacking something in a specific position, I'm bouncing around the screen like a DVD logo. Expect to see this in every autoscroller segment, and look carefully to see if Astro ever reaches an exact corner pixel, because I don't remember if that happened whilst making this movie.

One minor detail that isn't immediately apparent is that during waves where I'm waiting for an enemy to enter from the top/bottom of the screen, I'm holding Up/Down respectively; this slightly displaces the Finger Laser hitbox and causes enemies to start taking damage a frame or two earlier. A couple of the waves in this segment were surprisingly difficult to kill as soon as possible; the wave at 4:08/frame 14800~ in particular was very troublesome to find enough frames to be able to reach the bottom-most enemy in time to kill it in order to start the following wave sooner.

The final wave of enemies is not killed, because it saves no time to do so and attacking only serves to introduce extra risk of generating lag frames.

The Artificial Sun loosely chases Astro around the screen, and enters a second phase at 70% HP; the objective is to ensure it's in the center of the screen when this phase transition occurs, as it then wastes no time moving into position to begin the second phase. For whatever reason, I was unable to find a position where I entered this transition with 0 frames lost, but this transition in the movie takes no more than 2 frames longer than it would if played perfectly.

The second phase shows how much lag can be generated in this game when too much is going on at once. Unfortunately there is no method to avoid this lag as the laser is the only weapon you have during autoscroller segments.

A trivial "miniboss" followed by a dark room. This room is pitch-black if the player doesn't have at least one point invested into Sensor, but the only timeloss is from having one extra textbox from Astro to progress through, and even if I didn't need as many points as possible into Laser, it would take more frames to allocate a Sensor point than would be saved from not getting this textbox. An optional miniboss/upgrade point can be accessed by leaving the screen on the right, this is skipped. An additional upgrade point can be gained by heading left after the the first drop. This is also skipped, albeit this upgrade point was part of the old RTA route.

Falling down the long drop without contacting any floors and losing downward momentum was a little tricky, but there's enough frame data with changing direction midair to work with. The bats in this segment are awful as they move around randomly and can end up in unfavourable spots, which I believe happened after the Wally upgrade point; I immediately Arm Cannon the hidden statue to the left to unlock the door at the end, but a bat moves onto Astro's location and forces him to clip left, losing a few frames. I tested many different variations of moving through this entire room, however, and am sure I did not manage to find a net improvement over how this segment is played in the movie.

A very trivial segment. With the current upgrade spread, the large robots are defeated with a full Arm Cannon followed by literally any other source of damage. For the first robot a punch is used, and for the screen-wide wave directly afterwards, a Finger Laser as it hits every enemy simultaneously.

This elevator section was a massive headache to work on, and actually caused me to stop working on this movie for several months. There are a couple of rules at play here: Two types of enemies will spawn; bats and bees. Bats will infinitely spawn until twelve bees have been killed, so I avoid killing the first bat for as long as possible until it will not cause any additional spawns. The second optional upgrade point is also collected here from Magma, who is exposed simply by attacking a specific part of the background. As this is an autoscroller segment, this is very missable in RTA play.

Once the enemies have all been defeated, a cutscene plays showing the elevator docking at the bottom of the screen. I had great difficulty in optimising this segment due to the apparent presence of a framerule in this cutscene; much of my testing yielded no timesave whatsoever despite killing the enemies sooner, as the elevator would dock at the same time. After redoing the entire segment with a different kill method that saved some extra time, the elevator docked about as early as possible, saving over 200 frames. Due to this, I am convinced that no substantial improvement is possible on this segment unless a similar timesave is discovered in the kill order.

Pook is a very mechanically simple fight, but there are a surprising number of details in order to optimize it. Pook will always begin the fight by cycling through his four different animal forms: fish, monkey, lion and bird. Each transformation is triggered by dealing a certain amount of damage to him. After each animal form has been seen once, he will randomly choose any of the three forms he is not currently in for the next transformation. Lion is by far the worst transformation as it incurs forced timeloss due to the green force-field that surrounds it upon spawning, so the mandatory appearance at the start of the fight is the only time it appears. The force-field also remains active for a random number of frames, which can be mitigated by standing behind the boss in order to force him to turn around. Bird is the next-worst form, as it begins its movement by rising into the air; this actually delays the next transformation sequence until Pook becomes grounded again. Thus, once the random transformations start, I manipulate getting only monkey/fish transformations for the duration of the fight by delaying my attacks slightly.

This is the start of a major deviation from the RTA route; the upgrade point from Pook is allocated to Laser instead of Shot, which is the secondary stat in RTA runs. I was convinced that there was no value in using the Machine Gun in a TAS and that it would actually be slower to do so, and so I chose to upgrade Laser instead as it is both faster to allocate points to, and results in more immediate timesave due to higher overall DPS. The vertical silo section was a big problem area to work on as enemies can spawn both at the top and bottom borders of the screen, rapidly becoming unmanageable. Thankfully, an RTA strat discovered by Sonikkustar has great utility here; by remaining at the bottom of the silo for several seconds, enemies are forced to spawn in approximately the same place, making it easy to gather them up and kill them simultaneously. One downward boost is used to set up a final jump to clean up the remaining enemies whilst rising to the top of the silo, and the screen unlocks before reaching the top of the screen.

One enemy is skipped altogether during this segment; when the screen unlock occurs to reveal the first Purple enemy at the end of the segment, this is due to the absence of a robot that is supposed to spawn to take the place of a robot killed directly beforehand. If all enemies in that preceding wave are killed and leave the screen before the next enemy spawn occurs, the screen simply unlocks and the game progresses.

Another very trivial screen. Multiple consecutive Arm Cannons is the fastest way to defeat the Goblin mech and progress to the next area.

This segment is the second instance of Astro's vision being impaired due to not having any points allocated to Sensor; with two points the fog in this room doesn't display, but it doesn't hinder progress anyway. The third and final optional upgrade point is collected here, from Fumoon. This upgrade point also causes additional timesave that isn't obvious, and facilitated the change in upgrade point routing mentioned in Stage 2-3 when I discovered this in RTA play; if the player progresses without collecting Fumoon's upgrade point, the following enemy waves are incredibly laggy and the game plays at virtually 50% speed. If Fumoon's upgrade point is collected, this lag does not occur. I have no idea why this happens, but it does, and I didn't discover this until attempting a 100% run since I wasn't collecting Fumoon's upgrade point prior to that. Swapping Rainbow Parakeet's upgrade point in 2-3 for Fumoon's in 3-3 is a net timesave just from the shorter path needed to collect the respective points, but the fact that it also results in so much lag reduction saves a VERY considerable amount of time, even in RTA terms.

Unfortunately I still need to wait for the piston cycles to allow me to progress into the second enemy wave. This time is "made back" by managing to damage-boost on the piston to the right as the screen unlocks and getting clipped past the piston, though.

A simple segment in principle, but the first enemy wave was surprisingly difficult to manage. In RTA the standard method is to use a Machine Gun to hit all the small enemies, but without any points invested into the stat it fails to kill them. Thus I had to find a way to gather them up quickly, which seemed impossible at first due to how some of Astro's animations work; it takes several frames for Astro to jump after inputting A, during which time he goes through a squatting animation. If another action such as a Punch is inputted before this animation finishes and Astro becomes airborne, he instead remains grounded whilst punching. Therefore, it is impossible to perform a jumping punch which has an active hitbox as soon as you leave the ground, it must necessarily become active several frames after you leave the ground. Thankfully I was able to find a single frame where I could jump from a specific part of the slope, and be both close enough and low enough to hit the three bottom enemies, dragging them upwards with me.

Atlas is a relatively simple boss fight, though the attack order is changed from the RTA method; the first action performed is a Finger Laser, until Atlas has little enough remaining HP for a full Arm Cannon to end the first phase of the fight. Whilst Astro is in the Arm Cannon animation, he has a strange form of intangibility that prevents him from taking damage from certain types of attacks, but not others. Atlas' plasma cannon is one of those attacks that simply doesn't hit Astro during the Arm Cannon animation.

Phase 2 involves positioning Atlas whilst he is invulnerable; though he doesn't take damage, he can still be physically moved, so I use this opportunity to position him so that after he boosts right to hit Astro, then starts moving left again, he will end the fight in the exact position that the following cutscene starts on. Zero frames are lost after the fight due to this. I am not convinced that there is a faster method for clearing this fight, nor that it is relevant that Astro gets hit during Atlas' charge, as Atlas is completely invulnerable during his charge in the same way that Astro is during boosts.

The first of a couple of stage segments which actually features a slower IGT in the TAS than in my RTA PB. This is due to the increased usage of Super attacks in RTA as a simple way to deal with screen-wide enemies, but it's not necessary or indeed faster to use these in a TAS. The method used to kill the third enemy wave just before Nuka looks really silly and counter-intuitive, and it is in fact 1 frame faster than just using an Arm Cannon. Thanks, game.

This segment was particularly troublesome until I realised that the flying platforms follow the same rule as every other enemy wave in the game; they must go offscreen before new platforms will spawn to take their place. With this knowledge, I ensure that the first four platforms, which always spawn on the left side of the screen, spawn as low as possible so that they exit the screen sooner. After this point, the remaining platforms can randomly spawn at any height, and on either side of the screen. Thankfully, as long as platforms spawn on the right-hand side, it is irrelevant how high up they appear as they will exit the right border before they exit the bottom border. Thus, I use input delaying and damage-boosting to manipulate platform placements so that I am able to exclusively aim towards the right. In RTA, this screen is typically seen as a "free screen" where there isn't any realistic timesave available as it will largely progress at the same pace each time. In this TAS, I managed to save 9 seconds, as shown in the table at the end of these notes.

Another autoscroller, more DVD movement. These segments, whilst tedious to construct, are not particularly involved aside from making sure to destroy enemies on the first possible frame where it is faster to do so. There are a couple of instances during this segment where I just DON'T destroy an enemy, once again this is because it turned out to be faster to allow them to survive and exit the screen on their own.

Carabs is a frustrating fight, not because it's difficult to execute, but because I'm convinced there is no method to kill this boss with zero frames of timeloss. You either have to damage-boost at some point, or waste frames by avoiding taking damage. There simply isn't enough time to kill the boss whilst maintaining constant damage, without taking damage yourself.

This segment required a great deal of RNG manipulation. The kill method for the first wave, whilst looking unrefined is almost certainly the fastest way to clear the screen. The enemies here are strong enough that repeated Finger Lasers will not kill them quickly, and using a kick to cluster the mobs is not practical as the two strongest "colours" of mobs, Red and Purple, do not suffer hitstun when you damage them. Doing anything other than an Arm Cannon whilst being faced down by the red mob simply results in Astro getting punched in the face and sent tumbling.

For the second, extended wave, this is where RNG manipulation takes place. Eighteen total enemies come onscreen, with no more than six being onscreen at any one time. New enemies appear to replace enemies that get killed, and they can spawn on either side of the screen. With this being a very wide screen, this can waste a lot of time. I delay inputs enough to ensure that enemies spawn exclusively on the right, until the end of the wave when the giant enemies appear. At this point it's not relevant whether they're on the left or right, as they're strong enough for an Arm Cannon to be the fastest way to kill them, and boosting to the right of the right-most enemy to push it towards the center works just as well as continuing to manipulate the spawns, which would cost extra frames to achieve.

An interesting note is that after the final wave is killed and the Black Looks upgrade point collected, Astro will return to 5-1 until he reaches the end of the screen. By already being at this point before the upgrade point is collected, the game places you straight into 5-2 instead.

Another segment in which the TAS IGT is slower than the RTA IGT, and it's again due to fewer Super attacks used. Using two Finger Lasers to kill the first wave proved slightly faster, which isn't the case for the second wave as those enemies are too strong to be killed with the same method.

The last autoscroller segment of the run, and appropriately contained the most difficult parts to optimise. The flying platforms in particular are a real pain since their movements are semi-random, and I needed to ensure they stayed as low as possible so that they exited the screen sooner. I ignore one enemy wave in this autoscroller entirely as it has no bearing on how fast the game progresses, so destroying them only risks to cause additional lag frames.

The miniboss thankfully gave me the ideal attack pattern without the need to waste frames manipulating RNG. When the first three weak spots are destroyed and the bottom opens up to reveal the cannon, it can use a few different attacks, only one of which is favourable as it remains open long enough to destroy in a single cycle. This is the one I naturally got when attacking as fast as possible.

The start of this segment sees Astro on top of the train, and there is a constant pushback preventing you from moving forward quickly. This isn't an issue for the first enemy wave, but it made figuring out a way to drop into the train quickly a nuisance, since I would normally consider something like jumping before reaching the ledge so that I can start descending with higher falling speed, but the pushback made this impractical.

The enemy waves inside the train were the only point of the movie where I actually disabled a background layer to make things easier; it's virtually impossible to tell where the enemies are spawning whilst working frame-by-frame in TAStudio due to the train obscuring the view of each end of the screen. Standard RNG manipulation for these waves, where I want to get them to spawn exclusively on the right. I wasn't able to achieve this for the first couple of enemies of the second wave, but was able to kick them to the right as further enemies continued to spawn and controlled every spawn thereafter.

Deadcross is a joke of a fight.

I did not expect the method used in the movie for the first enemy wave to be optimal, but apparently it is. Using the boost to travel upwards to kill the second set of enemies sooner turned out to be preferable to killing them later, but using the boost to move right. None of the other enemy waves in this segment feature anything particularly notable other than killing/progressing on the earliest possible frame as standard.

For once, kicks are used for their intended purpose in multiple waves during this segment: To turn enemies into projectiles that fly into other mobs and in turn send them flying. This gets all enemies onscreen so that a single Arm Cannon will destroy them simultaneously.

The wave of tiny enemies required a few different attempts before settling on the method used in the movie; the problem I was having was attacking the red enemy as soon as it came onscreen and having enough time to kill it before it damaged me in return. I eventually decided on taking an early damage boost so that Astro's invincibility frames would provide the time to do this, but a further problem arose: These enemies have a tendency to raise their shields if in close proximity and not hit quickly, making them completely impossible to damage until you jump away from them. I solved this by being far enough away to not trigger this behaviour from them.

A short segment which is pure movement and slope-boosting. The wheels rolling down the slopes can and will knock Astro back if he collides with them, so avoiding cancelling a boost whilst inside them is of critical importance, even in RTA runs.

I'm very grateful that I was able to find a fast method for this fight. Sharaku used to be the biggest run-killer in RTA runs due to having three special attacks he can use: Aztlan (Red), Mictlan (Blue) and Atonatiuh (Green). In the event that he uses his green attack, he becomes completely invulnerable for an extended period. I discovered some time ago that it's possible to consistently manipulate Sharaku's red attack as the fight begins by being underneath him, and whilst a special attack is in progress, he cannot use another. Thus, it prevented his green attack from showing up whatsoever and fights were much faster on average. However, the tradeoff from this is that Sharaku's red attack is one which forces the game to lag considerably. This was unacceptable to me, so I decided to try and find a method of fighting Sharaku normally without having his green attack occur. It did consistently occur at various points in the fight until I altered the rate at which I dealt early damage; after the first Arm Cannon, I switch to using the Finger Laser for approximately 10% of his HP, before switching back to Arm Cannon. This, combined with the movement pattern, prevented the green attack from appearing, and as each Arm Cannon deals 30% damage, the Finger Laser usage is required anyway. Very satisfied with the way this fight came out.

Stage 7 is a boss rush which begins with the Versatile robot, North. The player must begin this fight by baiting out a block from North by attempting to punch him, after which an Arm Cannon can be used as normal. This inflicts enough damage to begin the second phase of the fight, during which North will move around and act according to your position. Whilst to the right of North, he will regularly counter-attack you with an energy beam. This attack seems to be of the same type as Atlas' plasma cannon, as it can be ignored whilst Astro is in the Arm Cannon animation. A minor amount of time needed to be spent in this fight in order to get a favourable RNG value to carry into the next boss fight; it's fastest to begin phase 2 by using the Arm Cannon on the same frame as punching North, but this prevented me from getting the RNG I needed and it was necessary to change the attack order.

Denkou is the second boss and has the honour of being the shortest segment, and fight, of the game, clocking in at 5 seconds. This is intended to be a long and protracted fight due to Denkou's pattern of becoming invisible after exiting hitstun. The solution to this is to simply not allow him to exit hitstun. Denkou will always begin this fight by running away to the right, and will then either jump up to the next level, or continue running to the right. This jump is the RNG value that I needed to carry from North, as there isn't a fast way to kill Denkou without this jump occurring. There is a single frame, with perfect movement, during which you can catch Denkou with a punch as he is jumping up to the next level, whilst forcing him to get stuck against the wall as you use an Arm Cannon. Getting stuck against the wall like this is what makes this method work, as without this occurring, Denkou will get pushed offscreen and exit hitstun. Some additional time is spent using two extra punches on Denkou before finishing him off, to get another favourable RNG value for the next fight.

Brontus is one of the bulkiest enemies in the entire game, and a great deal of time is saved by not having to keep him stunlocked with Machine Gun usage. Brontus begins the fight here by using his energy blast attack; this is the RNG value carried from Denkou, as it is the only favourable way to conduct this fight. His weak spot opens quickly and I am able to position myself to use repeated Arm Cannons from across the room. The angle of the energy blasts is dependent on the frame data, thankfully as long as I get high enough I'm able to avoid all of the energy blasts without needing to spend frames manipulating their angles. Being at a large distance from Brontus forces him to follow up with a second energy blast attack, after which I can boost behind him and finish him off as normal.

Epsilon is the penultimate boss of the game, and a fight I was very anxious about coming into. This fight is trivial in RTA, but only because of Machine Gun abuse that stunlocks him like every other boss. It is borderline mandatory to do this due to the variety of attacks he can use which range from wasting varying amounts of time to just killing you very quickly. You would need to be extremely lucky to get a favourable fight that can be finished quickly with just Arm Cannons without stunning him. Thankfully, this run manipulates RNG. Epsilon chooses his dolphin-summoning attack to begin the fight, which is the most favourable attack to see; it's the only attack that the player has a chance of attacking through without being interrupted. The angles that the dolphins swim at are random, and after testing several variants I was thankfully able to find a series of positions with which I could narrowly avoid every dolphin. This attack DOES unfortunately cause some slowdown, but there is simply no better alternative for this fight.

At last we come to the final boss of the category, Pluto. Known as the World's Strongest Robot, he certainly has the toolkit to back it up. There are many different attacks that Pluto can use in this fight, some of which generate a lot of additional lag. Thankfully, I was able to avoid these attacks altogether. Pluto began this fight by jumping across the room and spinning; there is enough time to land a punch + Arm Cannon before he becomes invulnerable, after which I remain on the right-hand side of the screen. From this point I managed to get genuinely really good luck; the rest of the fight is nothing but his most favourable attack, a missile volley that causes next to no lag, but I didn't even need to manipulate this for the most part. He just... Happened to keep launching these as I continued to wail on him with first-frame Arm Cannons, and the fight is a done deal. It is difficult to overstate just how much time is saved on this final stage from not using the Machine Gun after every second Arm Cannon in favour of getting perfect RNG instead, but it makes the bosses look like nothing. I invite anybody to try this out in RTA and see if it really is that easy, though.

feos: Great run. If we discard whopping 21500 frames of lag #1036: josh_l.'s GBA Astro Boy: Omega Factor in 31:01.17 has, and the BIOS time this movie has, this run is still 03:47.52 faster. Easiest difficulty sounds justified for this game. Everything looks good, feedback was positive too. Accepting to Moons.

EZGames69: Processing