The object of the game is to collect the required amount of diamonds from each level then escape via the exit. Any diamonds collected over the amount will score double. A bonus life is awarded every 300 points.
You can be killed in several ways. If you run out of time, a life will be lost. Any object falling on you will crush you. If you move too close to the aliens, they will explode. Also, moving into the dreaded goo will kill you.
If you drop a rock on a ghost it will explode - but if you do the same to an alien 'x' it will change into diamonds.
Conversion barriers also make diamonds but it's up to you to find out how.
If you get trapped, you can push rocks or if you have any power you can shoot your way out.
If all else fails, you must sacrifice a life by hitting CLEAR.
< - Left, > - Right, A - Up, Z - Down, SPACE - Fire
P - Pause/Restart, CLEAR - Quit
The game will automatically load and run.