Sound Test
While holding Up, A and B, press Reset on the Control Deck. A screen will appear showing the sound selections in the game. Now you can press Up or Down to select a sound and B to hear it.
Re-Energize
When low on energy, press Start to pause the game, then press Up, Up, Down, Down, Left, Right, Left, Right, B and A. Then press Start to unpause the game, and your energy meter will be filled. You can do this once per game.