While playing, press Talk (the default key is "T") then 
type any of the following codes and press [Enter]. 

Code                Result
-------------------------------
god                - God Mode.
ammo               - Full Ammo.
armor              - Full Armor.	
health             - Full Health.
guns               - All Weapons.
kfa                - All Weapons, Full Ammo/Armor.
tears              - All Weapons, Unlimited Ammo.
poltergeist        - Ghost Mode.
gear               - Increased Health, Reflexes.
maphole            - Skip Level.