A shooting em up game in which the purpose is to fly through the solar system, destroying waves of alien attackers, before finally reaching Earth. Planets that must be passed before Earth is reached are Neptune, Uranus, Saturn, Jupiter, and Mars. It only takes two warps to reach Neptune, but all of the others, including Earth, take three warps to get to. Each time the player reaches a planet, they will be faced with a Challenge Stage. A bonus stage in which players try to destroy as many aliens as possible to accrue points. After reaching Earth, there is a Challenge Stage, followed by a very fast 'three warps to Neptune' stage. After this, the levels and the background music start over. This game was heavily influenced by Atari's Tempest and Namco's Galaxian.
Note: Invincibility cheats used after down to last life. The game is endless.