One bug I found is that when you put the camera to your face, then switch to portrait mode, exit the camera and enter it again, the camera comes up in the landscape orientation but the on-screen frame comes up in portrait, and if you press Ctrl, it switches to portrait mode from portrait mode. So I'd presume it's a problem with the camera's orientation being out of sync between the HUD and the physical actor.
But that's really minor stuff. Overall it's an incredible environment with nice mechanics to keep it entertaining.