In game instructions: The object of the game is to defend your planet from the menacing aliens. You are in control of a spaceship equipped with a laser gun and three smart bombs. You must attempt to destroy the aliens with the laser gun or the smart bombs. Smart bombs destroy all the aliens on the screen. User Summary This is a simple sideways scrolling shoot-em-up. It takes many elements from Defender (1980), copying all the enemy types (including the names!), but only scrolls in one direction and has no humans to protect. It also has elements of Scramble in that the player's fuel is constantly depleting and must be topped up by shooting fuel dumps. This was one of the first four games written by the founders of Superior Software in the autumn of 1982. This game and two others were written by Richard Hanson, the other was written by John Dyson. They were originally sold through mail-order on the back of a "small black-and-white advertisement in one of the early home computer magazines" in the run up to Christmas of that year. The success of this venture led Superior to grow into one of the largest early computer game developers and publishers. The game was later re-released with professional packaging.