Cavern Attack is a side view scrolling game where you control a submarine, moving up or down, to destroy as many monsters as you can. The screen scrolls constantly from left to right and you must avoid touching the sides of the cavern as you ram the monsters. The monsters have spat out torpedoes and these need avoiding and if you touch one or the sides of the cavern, then it is game over. There is an option to play a Slow or Fast game.