Press ENTER during game play and type "give me a big head", then press ENTER again. To return to normal size, press ENTER during game play, type "get my head back", then press ENTER again.
In the skirmish level selection menu, hold LEFT CTRL + RIGHT ALT + PAGE UP for about one second. Go back to the main menu, then go to "Arm Center". You should have every part and weapon available. Note: This also unlocks every level and round in skirmish mode.
