Cheatmode:
 During gameplay type the next codes:
 
 Code - Result:
 killemall - Invincibility
 bullets - 100 bullets
 cells - 50 cells
 drones - 25 drones
 armor - 100 armor
 shield - Full shields
 zap - Destroys a few invaders
 go?? - Go to level XX
 noammo - Infinite ammo
 warp - Next level
 top - Push invaders back to top
 life - 1 life
 upgrade - Upgrade ship
 nitro - Nitro filled invaders
 nuke - Nuke missiles