Intro was neat. Some coins seemed to kill you, is that accurate? On the second level the last coin always killed me when I grabbed it, then on one of the green levels. Or it might be that the character gets too close to the edge of the screen while falling and it triggers a death? Not sure.
I also didn't realize the rewind mechanic existed at all until I got many stages in. Sometimes is would rewind a bunch, other times just a couple frames.