While playing the game, press [Ctrl] + [Alt] + ~ to display the console window. Then, enter one of the following codes and press [Enter] to activate the corresponding cheat function:

Result - Cheat Code
God mode and infinite Spirit mode - god
All weapons with maximum ammunition - give all
No clipping mode - noclip
Ignored by enemies - notarget
Extra health - give health
Extra ammunition for all weapons - give ammo
Spawn indicated object - give [name]
Spawn indicated object - spawn [name]