Level Select:

While playing, hold Ctrl-Alt and type "QWERTY". You can now access any level without needing a password.

Unlimited Time:

Enter the following exactly as written "SAGITTARIANS MAKE BETTER LOVERS". This code removes the need to collect keys and gives unlimited time.

Extra Points:

To get extra points on your score, go to any level you have beaten, and beat that level again.

Level Skip Plus:

Start the game and press "F" until the screen turns upside-down. Now enter the following exactly as written "I THINK THEREFORE I AM". Now you do not have to collect any more chips and can skip the level by pressing "C".