Cheat Codes
While in game press "Enter" and type " " (include the space after ), followed with the one of the codes from below and then press "Enter" to enable the code.

Cheat Code - Effect

mpcanthurtme - God Mode
mpschuckit - Add Weapons & Ammo
mpsmithy - Full Armor
mpkohler - Full Ammo
mpbeamme - Beam Player to Level Start
mpsixthsense - No Clipping
mpicu - Third Person View
mptachometer - Show Speed Info
mpsizeme - Show Size Info

Change Species While Playing
mpmorph

Type the following texts after mpmorph to enable the species.

marine duke
drone
predalien
praetorian
queen
exosuit
lightpredator
mhawkpredator
heavypredator
predator
chestburster
eisenberg
runner
droppilot
convict
combatsynth
apesuit
femalelabtech
grenadier
laboror
dunya_ai
ivan_ai
malelabtech
minigunner
sadargunner
obrian
pocguard
pulseriflegirl
railgunner
rykov
smuggler
tamiko
guard
guard1
guard2
guard3
officer
scientist
harrison
merc1
merc2
merc3
merc4
scientist1
scientist2
scientist3
smartgunner
malelabsynth
hazmat
scientistchief
pocofficer
mccain
pulserifleguy
femalelabsynth
guardofficer
facehugger

Morph
Hit the enter key, then type mpmorph (whatever you want to morph into). For example: mpmorph queen.