Defender for the Atari 5200 is an arcade-style shoot 'em up game, originally developed by Williams Electronics. Set in a distant future where players pilot a spacecraft defending humanity from an alien invasion, the game's objective is to defeat waves of invading alien forces while protecting astronauts on the surface of a scrolling planetary landscape. Defender features fast-paced action, with players navigating horizontally across the screen, shooting enemies, dodging attacks, and rescuing astronauts to earn points. This game is renowned for its challenging gameplay and is considered a classic in the shooter genre.