A lot of nice obstacles in there but it seems a bit messy from time to time.
The most problematic thing is that you slow down too much in the jump and you feel very much out of control in the air. So getting score from the blue circles isn't really useful most of the time.
I think if you would stretch out the obstacles a bit further away from each other you could speed up the gameplay a bit and have the player feel more in control in a much faster race with the same difficulty. :)