IDK if it's just mee but mousewheel scrolling isn't working, (Windows 7, Chrome if significant) and that pretty much kills it. The icon navigation isn't available until you've scrolled some, and grabbing the scrollbar is somewhere between undesirable and not at all functional. What I saw of this looks very nice, though!
Same here, Windows 7, Firefox.
I don't think mouse wheel scrolling was implemented at all. This may be on purpose, since scrolling fast with the mouse wheel would detract from experiencing the (sometimes boring) grandeur of the universe.