It's supposed to look like a video game level. There are a lot of different hardware configurations. Could you please go to http://webglreport.com/?v=2 and tell me what "Unmasked Vendor" and "Unmasked Renderer" say?
For Firefox, could you open up the console with F12 and tell me what that says as well?
FF and Safari don't work at all. Chromium shows something, but it isn't clear if I am seeing what is intended as the site has little to no information as to what it is.