Zool Cheats (PC)

Type GOLDFISH and hit [Enter]. This enters a cheat mode whereby if you:
  Press [1] - you become invincible for a short while
  Press[2] - enables you to skip to the end of the level
  Press[3] - enables you to skip to the end of the world

Type STRETLAMP at the options screen. This gives you: 

  [Grey +] Level up
  [Grey -] Level Down
  [1] Invulnerability
  [2] Lose a life (why?!?)
  [3] ??
  [4] Restart Level