I can't give you a good review on this.. I can offer some creative criticism, though.
1. Leveling up doesn't feel like an accomplishment when the only thing that changes is how long you have to get. Change the background, even if it's just changing the color of things to give the illusion of a day, or season cycle.
2. The obstacles sometimes appear an inch from your face, giving you no time to react. Meaning no matter how good you are, the only thing determining your progress is luck.
3. SOUND! It's the 21st century and you put out a game with no sound what-so-ever? Hell even just some free generic sounds would have been an improvement.
4. This is more of a personal opinion, but it would have been neat to instead of turn into a butterfly at the end of a level, get a point of some sort, and an upgrade menu to spend it at.