[FrankenPC]

I found I could only rotate for about 90 degrees plus/minus. I tried to circumvent the problem by dragging my cursor outside of the window and bringing it back in on the opposite side so I could continue rotating. Strangely, the game sensed I had come in from the opposite side and reset the rotation to the exact same 90 degrees. It's purposefully attempting to be infuriating.

[mundo]

You need to let the browser capture your pointer.

[FrankenPC]

I use Chrome. Is that a specific setting?

[mundo]

On FF it seems sort of fiddly. It should capture (or ask you if it can) any time you click in the window, but in practice sometimes I have to click twice, sometimes I have to right-click and then cancel the RMB menu, etc. YMMV...

[malexw]

On a Mac with Chrome 43, I had a small pop-up at the top of the screen that asked me to allow the page to capture my mouse input.