Overall I am very happy with it, not only is it my first proper html5 game but its also my first proper box2d game. In the past I have played and tested with both but never put them into a commercial game. I was very impressed with HTML5 performance and see it as a strong contender to Flash games, the biggest limitation is the slower mobile phones with out of date browser but it is only a matter of time before these are obsolete :)
To build the game, we used RUBE, this made the process very enjoyable.
To play the game you will need to view it on Mobile or emulate it: