░ Pros> Tilt mechanic.
▒ Cons> Lack further exploit the possibilities and resources of the difficulty.
▓ Devolution> At the moment, the game seems to be a sketch of what could be in the future, but this requires more experimentation when designing the difficulty:
If the game limit will be marked by the Skill of the player, it should be the principal axis of development.
In general terms, you have to review the relations between the existing resources and integrate them in a better way. It would also be good that the music not only accompanies but mark time of difficulty, plus it's a good resource to break the sense of repetition and helps immerse the player in the game.
Particularly I think you should play your own game and relieve possible moves that the player can take as technique (like hitting the walls provides a kind of double jump), then rebuild the obstacles in relation to which techniques are best to overcome it and what no, leaving the player discresion more than one option to overcome an obstacle (as in "Barrier X").
Beyond that, it would be interesting to know if you thought about developing this game for phones or tablets, exploiting even more playability by tilting (and adding a physical challenge).