Massively Multiplayer Online Asteroids

It's just like the 1979 Asteroids, except it runs in your browser and the "asteroids" are other people.

This take on Asteroids is built in HTML 5, so it runs in your browser (assuming your browser isn't Internet Explorer). The original game, published by Atari, was released 13 years before the first HTML standard was published by the World Wide Web Consortium. Try building Asteroids with this.