Here's an unofficial clone (make of that what you will) of an immensely popular classic arcade video game of 30 years ago. (I actually played this at the arcade as a kid). You pilot a ship in a top down view of space and shoot to destroy clumps of asteroids drifting slowly by while avoiding colliding with them. Upon getting destroyed, larger asteroids break up into smaller faster moving asteroids which also must be destroyed while the occasional flying saucer will fly by and try to blow away your ship. Try to rack up as many points as you can over 10 different levels.
To play, use the up arrow key to thrust your ship forward and the left/right arrow keys to rotate your ship left or right respectively. There is no brake or reverse and your ship will drift some when you let off the gas (release the Up arrow key). Use the space bar to fire your ship's weapon. You can also use the Shift key to warp your ship to a random location in space (at risk of getting destroyed by reappearing on top of an asteroid).
For a more graphically advanced version of this game, see Maelstrom.