During gameplay press the '~' (tilde) key to display the console window and then enter one of the following case sensitive codes (without the quotes) and press 'Enter' to activate the corresponding effect.
younlock God Mode: Enter 'please god'
younlock ALL Weapons and Ammo: Enter 'please giveall'
Kill ALL Monsters on Level: Enter 'please killall'
please god - God Mode please refresh - Fills Up Energy please fly - Fly Mode please ghost - No Clipping Mode please tellall - See All Messages please giveall - All Weapons & Ammo please killall - Kill All Enemies on Level please open - Open All Doors please invisible - Invisibility
The ghost mode is the most needed for me, because with it you can fall anywhere, you'll just fly out. EnJoy!