My mouse didn't seem to lock to the game window so I could only turn so far before my mouse hit the edge of the screen. Other than that it is a cool game to play around with!
Did you click "Allow" when it asks to look the pointer? (seems to work in FF and Chrome)
Ah okay, I notice it now that you point it out. Was hard to notice the small popup while I was focused on looking at the game not the little window above it that popped up :/