Asteroids!

Fight for your home planet and defend it by shooting down the asteroids which are mysteriously attacking it. Shoot with space, control with left/right, apply a little thrust with up (I know, ther isn't a brake!) and aplly a Proton Wave every 500 cycles. The Proton Wave destroys everythin in it's path. You get 15 points for shooting Asteroids, 25 for shooting the tiny ones. The points get added to 10 every level. You advance to the next level if you clear all the asteroids. Have fun!