Cheats:

 In the demo version you could change things with

 GABBAGABBAHEY   You lose everything but your life
 ZINGERMANS      Invulnerability
 MOTHERLODE      Mega-Wowie-Zowie
 ALIFALAFEL      Accessoires
 EATANGELOS      Homing missles
 CURRYGOAT       All keys
 JOSHUAAKIRA     Full map
 WHAMMAZOOM      Level warp
 ERICAANNE       Bouncing weapons
 BITTERSWEET     Dizziness
 PIGFARMER       "Hi John!!!" or "Bye John"

 And for the registered version you have:

 ALMIGHTY        Invulnerability
 ALIFALAFEL      Accessoires (Afterburner, Ammo Rack, Headlights)
 BITTERSWEET     Fisheye-effect, dizziness
 PIGFARMER       Hi John! / Bye John! (shrink your window size to see
                 what4s going on!)
 FREESPACE       Warp to level 1-24 ( not to secret levels )
 GODZILLA        Displays a funny message twice
 GOWINGNUT       Makes the guidebot go berserk and kill all enemies
                 with all kinds of missiles
 SPANIARD        1st use: Kills all robots in the mine
                 2nd use: Kills Boss robot or the guide-bot if there
                          is no Boss
                 3rd use: Kills the Guide-bot
 LPNLIZARD       Homing weapons

 The lose-all-but-1%-of-shields-and-energy-cheats:

 GABBAGABBAHEY, ZINGERMANS, MOTHERLODE, EATANGELOS, CURRYGOAT,
 JOSHUAAKIRA, WHAMMAZOOM, ERICAANNE

 Since v1.1 in the full version also work:

 DELSHIFTB       Kills the reactor and guides you to the exit
 FRAMETIME       Frametime
 HELPVISHNU      Doubles the guidebot
 HONESTBOB       Lethal Weapon part 999
 ORALGROOVE      Groovy keys
 ROCKRGRL        Full map
 SILKWING        1x = robots fight each other
                 2x = commit suicide
 DUDDABOO        Ricochet
 BLUEORB         Boosts shields

Command line parameter:

-superhires :  Adds 1024x768 and 1280x1024 to the screen resolutions
               menu.