Galactic High Command have issued a directive for you to rid the Galaxy of all of the Federation's infiltrators. You must choose which planets to defend, and in which order. Once on a planet you are alone against the hordes of the Federation. Armed with a single-shot laser you will find arms pods from time to time which will give you - if rather unpredictably! - different weapons to fight with. Succeed in your mission on each planet and you will be able to go on to the next one, and once in space you will face a fierce inter-planetary battle in your fighter craft