The cheat sequence is different every time you pause the game.
Pause the game and press the buttons. You should notice that one of the buttons will produce a sound with a higher pitch. Now press another button. If you don't get another high pitched sound press the button that first made the sound and continue to try the other buttons. The cheat is a sequence of 5 or 6 buttons. Just think of the game SIMON and remember the sequence until you get it right. You will hear a different sound when you complete the sequence.
When you are walking into the pod base, try pressing the LEFT button and keep it pressed until you arrive at the crossway.. now all the level maps are upside-down..