Start the game with the "avp.exe -debug" command line parameter. Then while playing a game, press "~" to display the console. Then enter one of the following codes while playing as the indicated character (Marine, Predator, Alien or Any) to activate the corresponding cheat function (all character must be capital letters):

Marine:

Code Result
MOTIONTRACKERVOLUME # Change Motion Tracker Volume (# = 0.00 to 1.00)
MOTIONTRACKERSPEED # Change Motion Tracker Speed (# = 1 to 16)

Predator:

Code Result
GIMME_CHARGE Replenish Energy Supply

Alien:

Code Result
CROUCHMODE 0/1 Toggle Crouch and Crawl off/on

Any Character:

Code Result
ALIENBOT Create CPU-Controlled Alien
GIVEALLWEAPONS All Weapons and Ammo
GOD God Mode
LIGHT Create Light Aura (Input Again for Brighter)
MARINE BOT # Create # of Marine Bots
PREADOBOT # Create # Of Predator-Alien Bots
PREDALIENBOT Create CPU-Controlled Predator-Aien
PRAETORIANBOT Create CPU-Controlled Praetorian-Alien
XENOBORG Create CPU-Controlled Xenoborg
SHOWFPS Show Framerate
SHOWPOLYCOUNT Show Rendered Polys
LISTVAR In-Game Help
LISTCMD List Cheat Codes
TIMESCALE # Change Game Speed (# = 0.00 and 1.00)

Note: You cannot save your game with -debug activated.