I love your idea. I managed to get a top score of 3 :)
Do you think you could include all required references (the canvas, the math functions) with your script and fit into 560 chars?
Lol, i know it's hard as hell, my best is 20.
This game would definitely fit everything in that space. without issue because it is less then half the size.
I'll think about doing another game that is totally encapsulated like you suggest.
I did it! And the entire html file fits in less then a tweet.