Space Cavern is a shoot 'em up video game for the Atari 2600, released by Games by Apollo in 1981. Players defend an astronaut who has landed on a hostile alien planet, the Space Cavern. The screen is split into ground and sky, where dangerous creatures approach from both sides. The astronaut can move left or right and shoot at the alien beasts with a laser gun. The challenge is to survive waves of attacking aliens that emerge from the caverns. The gameplay is characterized by its simplicity, fast-paced action, and increasing difficulty as players progress through the levels.