At the main menu press [F2]+[F3]. CHEATS ON should be blinking.
Then press [+]+[Backspace] and type in these codes:
TURBO -- turbo mode
EVERY LEVEL SAVE -- level saving after each level
ALLOW SINGLE -- allow one player to play multi-player
PAPARAZZI -- [Ins] to screenshot
THE WHOLE OF CREATION -- disable cheats
SCOUSER -- enable cheat keys:
[Shift]+[F9] -- level skip
[F11] -- refill ammo
[F12] -- refill energy
