It gave me an idea...
When i was browsing an object panel i looked a webcam icon, i think if is possible to make augemented reality game? well, it's focused to interact with 3D objects, but i think it does 2D too.
Anyways, HTML5 has a weakness that can't interact with webcam like flash, maybe i think it's possible to make between <video> and javascript in the future... i'm not sure.
There a thing can bind to ARToolkit using Python.
http://mgldev.scripps.edu/projects/pyartk/
More info:
http://en.wikipedia.org/wiki/ARToolKit