World Championship Tennis

World Championship Tennis is usually known as "4D Sports Tennis", except in Europe, where this demo evidentially originates from. (This is the same series that spawned 4D Boxing.) It's a first-person perspective 3D (or is it 4D?!) game of tennis. You serve the ball, then try to keep hitting it back onto your opponent's side. The game looks pretty good for an early 90's game, with an impressive (albeit intentionally limited) perspective and some sound effects. The full version has tournaments and league play, but the demo only includes single matches with two pre-selected opponents.