Set on a grid you have to fight off the marauding Rigonites before your time runs out and you are destroyed by the Matter Zapper.
You start in the middle of the grid in which some gaps are blocked by walls and others by force fields deadly to your ship. Also on the grid are enemy craft which initially just move around trying to ram you but on later levels can shoot at you.
You have a laser with which to blast these ships when they are in the same column or line as you. You can move around and once you go in one direction you continue until you hit something or move again.
There are satellites that can be picked up for bonus points and an extra life at 10,000 points.
Good News
1. 40 levels of difficulty.
2. Fast reflex action.