Control the ship with the arrow keys, and press space to fire. Avoid the asteroids.
When you shoot an asteroid, it is replaced by two, and you get 2 points. If an asteroid hits the edge (meaning you dodged it), you get half a point. This game may look easy, but it gets very hard very quickly. The final score is determined by how many points you get (more is good) and the amount of time it took (less is good).