The game's basic storyline is a battle against an alien force. Between rounds, the alien commander taunts the player through synthesized speech. There is no conclusion to the game, although score is not kept after round 4. The game was unique for a vector-style game due to the ability to choose upgrades at the beginning of each round. Each upgrade allowed the player different abilities. Only one upgrade could be used per round-the upgrades ensured that each round played a little different from the last.