It requires the latest Firefox or Chrome browser (Firefox 14, 17 and Chrome 21 are tested).
Of course a faster CPU and graphics card will give higher frame rate. :)
You can either select one of the few provided saved games
For Chrome users: In order to play well in fullscreen mode, you need to type "about://flags" in address bar and enable pointer lock.
If you have poor performance, you may get better results if you disable compositing in your OS.
You can also try layers.acceleration.force-enabled set to true in Firefox about:config.
(use this at your own risk. a separate profile is recommended since you may have to manually remove it from prefs.js if your interface renders incorrectly afterwards).
If you have a Webgl error, you can try forcing webgl to enabled.
In Firefox, go to about:config, and set webgl.force-enabled to true.
In Chrome, start Chrome with --ignore-gpu-blacklist.