CHEATER!

GABBAGABBAHEY Cheats enabled!
SCOURGE WowieZowie Weapons!
MITZI All Keys!
RACERX Invulnerability On/Off!
GUILE Cloak On/Off!
TWILIGHT Shields Recharged!
FARMERJOE Warp to Which Level?

The following ONLY work on the REGISTERED version:

GABBAGABBAHEY Cheats enabled!
BUGGIN Turbo mode; everything (including enemies) speeded up
BRUIN Extra Life!
BIGRED SuperWowieZowie Weapons! (includes ALL weapons)
FLASH Illuminates a path to the exit
AHIMSA Turns off enemy ships' firing
BIOPSYTOYS Blows the reactor immediately
POBOYS Also blows the reactor immediately
ASTRAL "Ghost" mode; go through doors, etc. (NOT walls)
PORGYS MEGA WowieZowie Weapons! (Must be seen to be believed)
LUNACY Robots move fast, fire seldom