Browsing the web I found this game called Biolab Disaster (http://www.phoboslab.org/biolab/) which is a pure HTML5 game. It uses the HTML5 canvas element to full effect and this guy made an entire game engine around it. :nw:
Anyway, there is also a making-of video which can be useful to other game programmers. It's always interesting to see how other people program their games, especially when they know a thing or two about programming (which this guy obviously does). I especially like the sprite engine, every enemy powerup etc. is an entity which has animations.
http://vimeo.com/14920760
Despite the dry subject matter, it's quite humorous with some background jokes :D (mp3 on desktop and default search text etc.)
The guy who wrote Biolab Disaster has released HTML5 Game engine.
Looks half decent.
http://impactjs.com/
Great little video and game.