Menu: Up & Down to move up or down through selection. Space to select. In Game: Arrow Keys to move Pac-Man. Eat all dots (pellets) to win. Avoid ghosts. If you eat a super dot (or power pellet, call it what you want), you will have a short amount of time to eat as many ghosts as you can. When you eat a ghost they will retreat back to their home. That's about all you need to know.
