Hello, thanks for your feedback.
Unfortunately I am aware of all lacking elements, it would have been cheating about the 3 hours time limit if I added them.
I would want to say the 'clamp' happens only in webgl mode (browser game) because the mouse gets out of the game, and get stuck on the screen border (even if it's invisible). That said, I know how to solve this now, but it's too late!
Thanks again for testing my game.