I really like the concept and it seems well made, but I had a whole lot of trouble with the controls. When I tried to turn on fullscreen, the game just got a little bigger in the browser. This made it extremely difficult to do a lot of the jumps after the first few levels. Any time I would try to climb something, I'd end up flicking my cursor out of the bounds of the game or opening bookmark.
It seems like it could be really fun, but I had to give up pretty quickly because of this.