Cheat Mode
This cheat allows you to either watch the entire video of the game (except the ending), or to access any part of the house (but the puzzles are not solved for you). During the starting screen (the screen with the four skulls), type "Zaphod Beeblebrox", followed by "Eleventh Hour" (or possibly the other way around ;). If you don't hear a bell, try pressing F12 first, then retyping the above.