Really original and great idea, and I like the art and ambience (the clock ticking is a nice touch); however, I found it kinda frustrating because sometimes if you miss one jump, it forces you to do a lot of backtracking. Or sometimes you can get yourself into a situation where your only option is to restart the whole level. A simple "undo jump" (or something like that) would be really appreciated for impatient people like me :). To be honest I think all platformers could benefit from something like that in an assist mode or something.