The object of the game is to blast all of the space debris that is coming at you from all directions. The smaller the asteroid the more points you get. Also be aware that alien spacecrafts are patrolling that sector of space - their destruction is worth 100 points.
You start with three ships and get a bonus life for a score in excess of 25000. Each time you clear a sheet, the game will increase in speed and more debris will appear. There is a full wrap around screen. Display so if you thrust off the top of the screen you will reappear on the bottom edge. Good Luck!