Game Mechanics

Plasma Cypher

The Plasma Cypher is Strider Hiryu's primary weapon, and can attack in all 8 directions. It is also a button masher's best friend: you can attack as fast as you can mash the button. Attacking while moving does not slow you down. Charged Cypher Strikes double damage and range for a single hit. The charge time is very short, but it is significantly less DPS to try and chain Charged Strikes instead of mashing uncharged ones. The attack is still useful as a first hit on enemies and for breaking many shields. It also enables you to use Charge Boosts, explained in Movement Techniques. Of the 4 Plasma Types that you gain access to, Explosive Plasma deals extra damage and is the one you will use most often in a speed run. Ultra Cold Plasma turns enemies into platforms and disables them completely, which may have speed running uses. Switching equipped Plasma Type is instant and does not disrupt the current Charge Strike. An effective strategy for durable enemies on Hard Mode is to use a Charged Ultra Cold Plasma Cypher Strike to freeze them and immediately start mashing while switching to Explosive Plasma. The optional Magnetic Plasma Catapult Upgrade is even more effective for the disabling strategy, as it affects stronger foes like Brainwalkers who are immune to Ultra Cold Plasma.

Kunai

Ordinarily, Kunai are thrown in the direction of the left analog stick. Kunai can be thrown at any analog angle independent of your movement by using the right analog stick instead. This allows you to dispatch distracting or troublesome enemies without slowing down to go attack them head-on. Kunai damage stacks with each projectile and they can be "shotgunned" at close range. The optional Kunai upgrades dramatically increase their effectiveness if you take extra time to grab them, and Kunai become monstrous in 100% runs. If killing enemies is the priority, Magnetic Kunai work best at long ranges, while Explosive Kunai work better at close ranges. If disabling them is the priority, Ultra Cold Kunai work amazingly but some stronger enemies are immune. Reflect Kunai have little practical use in a speed run.

Damage and Knockdown

Certain enemy and boss attacks as well as some damaging terrain can cause Knockdown. There are 4 categories of damage. Light attacks like single projectiles from small arms fire tend to not cause any hitstun or knockback, but a barrage of many such attacks at once can. Medium attacks and some terrain hazards like heat coils will cause Soft Knockdown, which can be recovered from almost immediately. The recovery time does vary a bit based on the specific attack. It is possible to wall-climb through hazards that only cause Soft Knockdown by mashing Jump and recovering fast enough. Heavy attacks and some terrain hazards like trap-panels will cause Hard Knockdown, which slows the game down briefly to emphasize the hit. There is a period in which no recovery is possible after getting hit. These attacks are best avoided as the time lost can be substantial. The final damage type is lethal damage. This is only caused by terrain hazards specifically coded to cause it, even if they look like ordinary heat coils for example. Lethal damage plays Hiryu's death animation, and teleports him back to a preset location after dealing damage, but is not treated as a death. This teleport could be useful to save time in certain rooms. There are no techniques to avoid or recover from lethal damage. Techniques for recovering from Knockdown are explained in Movement Techniques. Protip: Don't get hit.

Gravity

Certain sections of the game change the direction of Gravity. In these sections, all directional inputs are relative to Hiryu's spacial orientation. Example: Gravity is inverted so you have to hold Up (which is Down for Hiryu) in order to slide. There are also spheres with their own gravity field that require constant spacial awareness to not mess up inputs. Mastering this skill is essential since a number of bosses are fought under these conditions.

Charge Strike Meter

That is the official name of the HUD item in-game.  Found under "How To Play" in the options menu.

Shortened as Charge Meter, often referred to by other names such as Rage Meter, the Charge Meter is the most important aspect to quick boss fights. The Charge Meter is filled by dealing damage: details below. When filled, Hiryu enters "Charge Mode" for 5 seconds, in which all attacks are 2X damage and 2x range i.e. they all become Charged Strikes, hence the name. The game slows down on activation, giving Hiryu brief Matrix style bullet time for easy damage dealing.

You lose Charge when you take damage, but the amount is variable with different attacks based on the damage taken. Example: walking into an acid glob from an Insect enemy loses about 10% charge, but getting punched by a Heavy Mech loses more like 25%. Avoiding damage in boss fights is thus more key in this game, not only for the usual reasons like hit stun wasting time, but because it delays your Charge Mode. You will lose all Charge after 5 seconds of not dealing damage.

EVERY individual hit always builds 2.5% of Max Charge, no exceptions. This value is multiplied by the number of enemies hit at once when applicable. This value assumes Charge Mode activates at 100%.

Cypher Strike:

Standard Cypher Strikes are the best way to build Charge; each hit grants 2.5% which means 40 hits to fill the bar. You may need to hone your button mashing skills to effectively run this game. Hitting multiple enemies at once with this (or any) attack multiplies the Charge gain. The equipped Plasma type makes no difference in Charge gain.

Charged Cypher Strike:

Although they do double damage, Charged Strikes still build the same amount of Charge Meter. The equipped Plasma type makes no difference in Charge gain.

Slide Assault:

Too slow at racking up hits means poor Charge gain, use only for movement and passing through enemies.

Kunai Throw:

The default Kunai throws 3 projectiles, but optional upgrades can increase this to a total of 7 projectiles. Charge built by multiple projectiles stacks, and shotgunning Kunai is HIGHLY effective and recommended. Unfortunately, in a speed run it is unlikely you will have time to grab tons of Kunai upgrades to actually abuse this fact. Furthermore, each projectile can only hit 1 enemy. The exception is the optional Explosive Kunai upgrade: Each explosion builds the usual Charge but has a small radius that can affect more than one enemy. This upgrade delays the damage, and Charge, until the explosion occurs.

Plasma Catapult

Builds the same amount as a Cypher Strike.

Option A "Dipodal Saucer"

The Saucers themselves deal collision damage and build Charge on contact. Cypher Strikes cause the Saucers to fire projectiles, which also build the same amount of charge additively with Saucer collision damage AND Cypher Strikes themselves. This results in a frenzy of damage at close ranges, and very efficient Charge gain. This is the optimal way to fight all bosses when in melee range.

Option B "Tetrapodal Robo-Panther"

The damage increases with each successive hit, but Charge gain is static. Can hit the same enemy multiple times based on terrain.

Option C "Robot Eagle"

This attack often seems like it builds more Charge than normal. It actually hits single enemies 3 times extremely quickly, and builds additional Charge. This is based on the enemy's life; If it could only survive 1 hit, only 1 hit's worth of Charge is gained.

Damage Dealt

THIS SECTION IS UNDER CONSTRUCTION

This section lists all the damage the player can deal relative to a standard Cypher Strike. This value was set to 10 for simple math without needless decimal points.

Plasma Cypher

Standard Cypher Strike

10 Dmg (No Plasma, Reflect Plasma, and Ultra Cold Plasma)

??? Dmg (Explosive Plasma)

??? Dmg (Magnetic Plasma)

Charged Cypher Strike

20 Dmg (No Plasma, Reflect Plasma, and Ultra Cold Plasma)

??? Dmg (Explosive Plasma)

??? Dmg (Magnetic Plasma)

Slide Assault

10 Dmg

Kunai

These Values are for a single Kunai, multiply by number of hits

No Plasma, Reflect Plasma, Ultra Cold Plasma

??? Dmg

Explosive Plasma

??? Dmg

Magnetic Plasma

??? Dmg

Plasma Catapult

Reflect Plasma

??? Dmg

Explosive Plasma

??? Dmg

Ultra Cold Plasma

??? Dmg

Magnetic Plasma

??? Dmg

Options

Option A "Dipodal Saucer"

4 Dmg (Saucer Collision with Enemies)

8 Dmg (Projectiles Fired)

Option B "Tetrapodal Robo-Panther"

??? Dmg

Option C "Robot Eagle"

120 Dmg (3 Hits of 40 Dmg each)

Glitches

Out of Bounds (OoB)

Discovered by EliteAssass1n

This glitch can be performed in any Save Room. To perform, simply climb onto the ceiling at the corner where the highest flat part meets the angle going down. Once in position, wiggle the shit out of top 180 degrees of the analog stick. Alternatively, try to mash Left, Right, and Up all at the same time. Once successful, Hiryu will have climbed up into the ceiling and be able to freely move outside the normal boundaries. Methods and locations to re-enter the map vary. Videos of the glitch can be found in Additional Resources.

Kunai Through Walls/Doors

Discovered by Pewable

Kunai can pass through some surfaces to hit the switches for Kunai doors from the wrong side. Many of these doors were intended to be one-way, but can be opened from the wrong side with this glitch. This does not work on all doors, and even when it does you must know where the switch is and have an unobstructed shot to it. Most optional Plasma Kunai upgrades make this glitch harder to perform, but the Magnetic Plasma Kunai upgrade makes it much easier as Kunai now readily penetrate all surfaces.

Ice Kunai Door Glitch

Discovered by Sainiku

Ice Door Kunai Glitch

Dragon Dance

Discovered by BumblebeeCody

During the first Ouroboros fight, you can reduce even negates the effect of the wind when Ouroboros accelerate. To do so, On PC put your refresh rate at 59 hertz, hold the left key on your keyboard and mash the right key. On console, wiggle your stick left and right constantly. By doing so you will stay close the blue tube, skip a phase and end the fight much quicker.

Dragon Dance 1 cycle setup

Discovered by SubStylee

For people that struggle or are new to the dragon dance. You can jump over the blue reactors on Ouroboros back and the wind can't push you allowing you to kill it quickly. You lose a second or two doing this if your mashing skills are average, but I think this could be a faster way to kill Ouro if your mashing skills are very good.

Dragon Dance 1 Cycle Setup