Cheat List:
Press TILDE to pull down the developer console and start entering cheats, then press ENTER.

noclip ... clipping mode on/off
give
Colt45Ammo
BazookaAmmo
MachineGunAmmo
Backpack
RifleAmmo
Machete
Colt45
Bazooka
Rifle
Bazooka
Machinegun
Landmine