Enter the following codes in CHEATS in the options menu:
Full Spectrum Warrior: Cheat Codes (English) Free Download
Bulgarianninja – Unlimited M203 grenades
Canadianvision – All enemies visible on the GPS
Mercenaries – Unlimited rifle ammo
Naked Op4 – No coverage for enemies
NickWest – Big heads
RocketArena – Unlimited ammo
Ha2p1py9Tur5tle – U.S. Army Version