God mode
First start the game with the -edit command line parameter. Then place the pointer in the game window and press [Shift] + Z, then press [Tab] to begin playing.

Unlimited ammunition
Note: This cheat involves changing a game file; create a backup copy of the file before going on. Now use a text editor to edit the "lisp\options.lsp" file in the game folder. Then enable mouse weapon switching in the file. Select any weapon besides the laser. Hold the Right Mouse Button when shooting that weapon and the ammunition counted for that weapon will be taken from the weapon on the left side.

Restore health
Save the game at a console, then right away reload that game. The game will restart with 100% health.