Using the CD-i controller and while holding down the second button click in the top left, top right, bottom right, bottom left with the first button. Then point to the letters in order "CHEAT" from the title "Creature Shock" and click on each letter using the left button (with the right button still held down). It's only the first 'e' in "Creature" that you want to click on. The Cheat Screen should now appear where you can turn Sound Effects "On" and "Off", Level Select, Main Menu and Credits are all the available options.