This is really awesome. Can you tell us which HTML5 features this used? I'm guessing Web Sockets (with node.js), Web Audio API, Web Workers, and lots more. Maybe it's easier to list what HTML5 features you didn't use. :-)
Yep. Web Sockets, Web Audio, and Gamepad API for sure. I'm not sure about the rest
Any chance of an online version that people can play?
Unfortunately, no. This is really just a tech demo. There's also security concerns that haven't been addressed yet.