This is one of the examples from my book on creating games and animations with HTML5 canvas. Have a play around, and even look at the source code if you'd like!

You'll learn much more by actually reading the book, so don't delay; pre-order today!

Much love, Rob Hawkes.

PS: Click and drag on the bottom asteroid to play the game. The objective is to knock all the other asteroids off of the platform. Good luck!