It's kind like Angry birds in certain respects in that if you hold down to long, it's instant failure. However, I think you made it too fast moving. I get it that he's running, but perhaps build up the speed to allow the user some forgiveness in getting used to the game.
I would also town down the background, and add a mute button to the music or at the very least a varying range of sound levels of the music. It was very distracting at times.
Perhaps making sure the background is a little more easier to discern from the platforms? Like using a dark shade of green in the background or a grayed out green?
Regardless, it was fun to play.