Spacewar! is the first graphical computer game, invented in 1962. The most retro of all retro games.
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 Robert A Saunders.
Original 1962 game code PDP-1 ported to Webapp Touch, Minimal changes such as iPad Touch controls and speed adjustments @BA.net
Computer science history
PDP-1 Restoration Project