The game actively punishes you for going faster by making the birds impossible to avoid at high speed and helmets or not, slowing you down to a crawl. Bad launch game, sorry.
Half the time left-click doesn't register right and you get trapped if your mouse moves a pixel outside of the window. Sad, because otherwise it's a fun game but that makes it utterly frustrating to play.
It's fun and as others have said, the physics are great but some of the timed bits (the rolling boulder, the raising/lowering water) are tuned WAY too tight with basically no room for wasting half a second and that's not challenging anymore, that#s jsut frustrating.
Fun concept and good ideas, but for a platformer (especially one that requires good timing sometimes) the controls are awful and much too unresponsive half the time.