Too bad this is flash based. An html5 version would have been more interesting to me.
EDIT: to be clear, it's genuine question, I'm really interested in high-performant graphics in HTML5.
Beyond that, all the code is in Javascript and out in the open, and the performance of Canvas isn't any better than Flash's software renderer.
You mention that hardware accelerated Canvas is going to arrive eventually in certain browsers, but hardware accelerated Flash has already shipped (as of last week). As well, Epic announced that Unreal Engine has been ported to the platform.
HTML5 is like 5 years behind Flash in terms of performance.
Also writing in HTML5 at the moment is like being given the total basics. Canvas, as an API, sucks. It'll get better, more libraries will come out, but god-damn it feels like moving backwards to take a step forwards.