It's a good idea. But you need to add a restart button! Or if you already have one, write it down somewhere. I had to refresh the game page every time I got stuck due to a bug... The design of your game leads to a lot of situations where you get stuck. I got my head stuck in platforms more times than I liked to admit. But when it happened I couldn't do anything but quit the game, and wait for it to load all over again. Granted, your game is not too big, so for now that's not a problem. But if you added more levels, expanded the game a bit... it would soon take a much longer time than people are willing to wait. If you add a restart button you don't have to worry about that!
Also, slow down the rewinding! It is too chaotic as it is now. It made me get stuck in walls a lot. I feel that the game does check if you will get stuck in the wall when rewinding, but it fails half the time. If you slowed it down, you wouldn't have to worry so much about that.
Overall, good job! It's an interesting idea. Well done!