Spacewar!
Spacewar! Screenshot: This is a virtual DEC PDP-1 emulated in HTML5/JavaScript running the original code of "Spacewar!", the earliest known digital video game. If available, use gamepads or joysticks (currently Chrome and Firefox only, see instructions-memo below) for authentic gameplay — the game was originally played using custom control boxes. Spacewar! was conceived in 1961 by Martin Graetz, Stephen Russell, and Wayne Wiitanen. It was first realized on the PDP-1 in 1962 by Stephen Russell, Peter Samson, Dan Edwards, and Martin Graetz, together with Alan Kotok, Steve Piner, and Rober...
Source: masswerk.at