It took me a few minutes to understand the "Run It Back" mechanic, but when I did it made for an interest mechanic. Would be nice if there was a timer on it though and adding the ability to start rewinding it when I wanted would be useful too.
I liked the layout of the levels, though I wouldn't put spikes under the box at the end, unless there was a check point near by, that's a little too mean I think :P