At its most basic level, Zero Gravity can be thought of as a Pong game, as the player controls a bat which must be used to hit a ball as it comes towards you. The main twist is that the gameplay is completely 3-dimensional, with control over the horizontal and vertical positions of the bat. The game uses a split-screen view, with the top half viewed from the perspective of Player 1, and the bottom from that of Player 2, even when only one of them is human.

Each time you get the ball past your opponent's bat, a score is added to a tally, and a number of points are awarded. Along the side-wall of the playing arena there are 8 tokens to be hit, awarding extra points, speeding the game up, deducting points from your opponent, and so on.