Yeah, the demo's short but very promising. Mivo, i was using Chrome and i couldn't hear the sound either, then i tried it using Firefox 11, same result. I guess the sound is temporarily not available for this game huh!?
Maybe they turned the sound off to avoid massive lagging. So far I've been able to get on, but there's never more than 70 people online at a time.
So far I've tested this in Chrome, Firefox, and Safari on Windows and Firefox on Android. It sound like HTML5 runs everywhere.
Well, almost. It doesn't run on IE9 because Web Sockets wasn't implemented. I'm going to check IE10 in a few minutes. It works in Opera, but you have to turn on Web Sockets.
Definitely cool stuff.