Needs a look over to fix final fatal errors
Good things about this game: Interesting concept, with good, flowing animations for the character, and simple artistic style that really compliments the game's style.
Now, for the bad parts: I often times found the time between button-press and reaction, lacking in speed enough to affect gameplay. There seemed to be a very random difficulty curve, starting with easy maps, a few difficult, or at least very tedious maps following immediately, then many more easy maps, then introducing a new object to the player, and repeating the process.
Several aspects of the engine are glitchy enough to be visible; graphics may randomly generate white blocks when you die, or are being "revived" for a frame or two. The physics engine needs backup codes for possible, and probable (given what you've allowed the engine to do) fatal errors. I was stuck in a large green-gray colored block (that was supposed to kill me with spikes on it's bottom-side) when I accidentally jumped during it's descent. The game completely stopped, and almost crashed the game.
Simply put, a few codes check for possible situations that would crash the game (that could be found with more extensive beta testing), double checking the graphics for errors, and some more organized maps arranged with difficulty curve in mind will really bring this game the few, but important things it is missing.