Great job!
I think the controls are very well tuned and I like the atmosphere and music. I had only a couple issues. The UI gets in the way of seeing branches. I would suggest making the UI smaller and/or moving it to the top of the screen. Last, I'm not sure if it was intentional but it doesn't seem like there is a penalty for hitting branches.
Otherwise, I like the way it turned out. Good luck with your future projects!