Nice work! This game has it's own unique beautiful look much like Angry birds!
In terms of performance from my Surface RT, it plays ok. We've had this discussion before - Win 8 ARM devices usually play appallingly with JS games, so it's not too bad still playable.
For a physics game it does get tricky to play when there's a bit going on, but it feels like it is playing normally at about 14-18 fps at a guess.
In any event, I've given you a rave review and 5* rating <img src="smileys/smiley1.gif" border="0" align="middle" />