I thought I was in an endless loop when the level seemed to circle around on itself, but then suddenly it wasn't the same, and there was a door to the next level!
First thing in the next level, I ran into an enemy (hitboxes are unforgiving), and went all the way back to the start of the first level, no checkpoint.
I'm not sure about the rewind theme, and other than the cute aesthetic, it's not very original. Keep it up.