The idea is very interesting. I've see it brought up in other games, but you took it a step further, allowing even the player to be rewinded. The game is good, but it needed a bit more polish: the movement and jump on the slopes wasn't really pleasant, sometimes it's hard to rewind things in mid-air, sometimes, when you die you die again the moment you respawn and in one level, once I died, the screen turned black and I couldn't continue. Also, english is not my first language, but i think there are some typos when you tell the player he can rewind himself