Press "~" to bring up the cheat menu. Enter the following to activate the specific cheats.

Code	Effect
give Backpack	Backpack
give Bazooka	Bazooka
give BazookaAmmo	Bazooka mmo
give Colt45	Colt 45
give Colt45Ammo	Colt 45 Ammo
give Landmine	Landmine
give Machete	Machete
give MachineGunAmmo	Machine Gun Ammo
give Machinegun	Machinegun
give Rifle	Rifle
give RifleAmmo	Rifle Ammo
noclip	Enable/Diable clipping mode