The first video game, Spacewar!, on the DEC PDP-1 in your browser

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 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 Robert A Saunders.
↫ Norbert Landsteiner

It’s wild to me that even for the very first video game, they already made what are effectively controllers anyone today could pick up and use. Note that this emulator can run more than just Spacewar!.