Defender is a horizontally scrolling shooter developed by Williams Electronics in 1980 and released as an arcade video game in 1981. The game is set on either an unnamed planet or city where the player must defeat waves of invading aliens while protecting astronauts. Development was led by Eugene Jarvis, a pinball programmer at Williams; Defender was Jarvis's first video game project and drew inspiration from Space Invaders and Asteroids. Defender was demonstrated in late 1980 and was released in March 1981. It was distributed in Japan by Taito.