Try Ejecta! It implements the Canvas API in OpenGL and is pretty fast :) http://impactjs.com/ejecta

Are there not already 8 million games almost exactly like this on iOS?

Now loads of people have asked me to do that. I am definitely gonna take a look at ejecta although it would be cool if some ios/android guy gets in touch with me. :)

I need to do some research on this topic.