Retro Pong

The 1972 arcade cabinet, rebuilt for a browser tab. Two paddles move up and down, a square bounces between them, and the first to five wins. Nothing has been added, which is the reason to play it: there is no upgrade screen, no currency, and no tutorial, so the whole game is visible within a second of loading. Retro Pong is the shortest possible answer to the question of what two people can do with one keyboard, and it still holds up better than most things built on top of it.