No cheats or codes, just a few unlockable items. Nothing to make things easier to get through.
Alien hunter costume- Kill 50 aliens(Bug hunt mission)
Bad blood costume and maul upgrade- Destroy the big computer up on the topat the start of the level.(The new flesh mission)
City hunter costume- Kill all snipers at the area where you have to kill the lieuteants.(A night to remember mission)
Dark blade clan costume- Ignore the first set of enemies and go and find a man to kill.(Extinction event)
Jungle hunter costume(PREDATOR)- Kill irish boss in midsummer night's massacre mission)
Ritual Armor Costume- Destroy 3 series of Vehicles that have Stolen Technology. (Under The Gun Mission)