Restore health:
Enter ImJackCarver as a case-sensitive code.

Unlimited ammunition:
Enter UnleashHell as a case-sensitive code.

Feral Attack in the early levels:
Enter FeralAttack as a case-sensitive code.

Unlimited Feral Attacks:
Enter Bloodlust as a case-sensitive code.

Unlock Evolution Game:
Enter GiveMeItAll as a case-sensitive code.

All maps:
Enter GiveMeTheMaps as a case-sensitive code.
NOTE: The effect of this code is permenant. If you want to disable it, you'll have to delete your 360 profile.