Oh, this is really neat! I love this idea, and I've actually been working on one of my own for a little while, though I don't have it online yet and it's HTML based, not WebGL. A while back in my blog, I actually made a link post for online Operating Systems, but those were all real ones (Mac OS 8, Windows 95, etc). I've been thinking about making a post of a collection of fantasy Operating Systems also, since there seem to be a number of these projects around.
Always great to see a new one, and I like the aesthetic it's got going on. I like how you can tell it was originally based on Win95, but it's grown to have its own quirks over time.