Passcodes in the game can be found on various notes that are scattered throughout Sudra. The passcodes are 12-letter phrases that can be entered into the Passcode Tool in the format XXXXXX-XXXXXX (the game will automatically enter the hyphen).
The Passcode Tool only has room for 5 passcodes at a time. Passcodes that have been entered can be edited, cleared, activated, or deactivated. Upon activating a correct passcode in the correct location, the player will hear a sound effect indicating the passcode has taken effect. See below for a list of passcodes and their effects.
If you choose to edit a Passcode, you can use the Square Button on PS4 to delete characters.
List of Passcodes
|AXIOXX-XXXXXX||Disables Trophy acquisition. End-game stats screen will display "Cheats: On".||Guesswork||The important part is "AXIO". See the Parametric Passcodes section below.|
|CUTSCE-NE0001||Replays the game's cutscenes. Valid values range from 0001 to 0044.||These are in the same order as they appear in-game, except 0040 is the intro, 0041 happens in the middle, 0042 is the ending, and 0043/0044 are the two bonus scenes.  WARNING: Save first! This can sometimes cause the game to become unresponsive!|
|DALKHU-SUBTUM||Reveals a door in the upper-left corner of the lowest-left room in Eribu, allowing access to the Orbital Discharge room.||Written on the wall in the same corner of the room.||Using REVEAL-SUDRAN and building a cypher table of corresponding letters you can manually translate the Sudran letters on the roof of this room to obtain this passcode.|
|DINGER-GISBAR||Opens a wall in the FlameThrower room in the upper-left part of Eribu||Written in Proverb (Note).|
|IKKIBU-LABIRU||Reveals a door in the upper-left side of Eribu, leading to a Power Node Fragment.||Glitching the red column in this same room.||The code appears as the top line of the Address Disruptor's white garbage characters when you use it on the red column, written in Sudran. You can either translate it manually or enter the REVEAL-SUDRAN code.|
|ISKART-EHANZU||Opens a wall in the large lower-middle room in E-Kur-Mah, allowing access to the Quantum Variegator.||Glitch the dark green moss enemies (Hopping Shrubback) in this room.||Glitching the darker green moss-like enemies (the ones that don't attach to you - Hopping Shrubback) in this room will cause them to begin spelling the code.|
|JUSTIN-BAILEY||Changes Trace's outfit to a yellow speedo, gloves, and boots.||This is a nod to the original NES Metroid game. Entering JUSTIN-BAILEY in Metroid's password system would start the game with a number of items, and Samus wearing a pink leotard.|
|REVEAL-SUDRAN||Translates notes written in the Sudran Language||Sudran Translation (Note)||Gir-Tab assisted in the creation of this Passcode.|
|REVEAL VYKHYA||Translates notes written in the Vykhyan Language||Vykhya Translation (Note)|
|TRACK#-######||Plays game music.||Decompiling the game code.||The code will change the in-game music according to the number you select, ranging from TRACK0-000000 (the menu theme) to TRACK0-000018 (the credits theme).|
In addition to the "normal" passcodes listed on this page, the game can be modified using "parametric" passcodes. Parametric passcodes are "cheat codes". They are hexadecimal representations that are fed into the game code, which modifies them with an algorithm to reprogram the game engine. @TehMillhouse discovered this by reverse engineering the game code. You can check out his information at this link.
When you enter one of these codes in the Passcode Tool, the game will prompt you that trophies/achievements will be disabled, and ask if you wish to proceed anyway. Additionally, the end-game stats screen will display "Cheats: On".
When asked about the Passcode "AXIOMX-XXXXXX", Tom Happ hinted about these "cheats", saying "Beat the game in Story mode, then pay close attention to what happens next."
The following in-game properties can be modified using parametric passcodes:
Useful Parametric Passcodes
Because of their algorithmic nature, parametric passcodes produce a LOT of possible values. Therefore, while not a complete list, the table below contains some of the more useful "cheats". For a complete list of possibilities, use the code generator found here.
|AXIOJY-TSLSXC||Sets Gravity very low. Trace will be able to jump the full height of a save room.|
|AXIO8V-HDOTN6||Store a maximum of 6 Address Bombs instead of 3.|
|AXIO8D-PKC64X||Bioflux Accelerator will shoot much faster.|
|AXIOGX-XJYCYA||Invulnerability. "God Mode". Damage taken reduced to 0.|
|AXIOMG-X02196||Big Projectiles and Big Drill|
|AXIOP8-3NWXAL||More Damage from Weapons and Drill|
- See the main article on github for more on this discovery.
- From his Reddit AMA