Tennis for Two is an early video game which was exhibited Brookhaven National Laboratory’s annual public exhibition and considered by some definitions to be the earliest video game ever made. It was on display for three days when originally displayed and returned the next year with a bigger oscilloscope screen and ability to adjust gravity (moon or Jupiter).
The game simulates a game of tennis on an oscilloscope attached to a Donner Model 30 analog computer. Players used custom made aluminium controllers with knobs to angle their shots, and a button in order to hit a ball back and forth. The ball is affected by gravity and uses a side view. The ball can hit the net or go out of bounds.