Defender is an arcade video game developed and released by Williams Electronics in February 1981. A shooting game featuring two-dimensional (2D) graphics, the game is set on a fictional planet 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' first video game project and drew inspiration from Space Invaders and Asteroids. Williams planned to display the game at the Amusement & Music Operators Association (AMOA) trade show, though development delays resulted in the team working on the game up until the show started.