Holy levels! (Loads of em)!
This game is very well polished for a jam game. In terms of the mechanic, I think this is a VERY solid execution of the mechanic of using the player after image in puzzle solutions. For one, I think the timer adds a good sense of novelty to the experience over other platformers that use this mechanic. Your implementation of the afterimage mechanic blew me away as soon as I got to level 6 though, when I found out that after images save velocity and not just position.
The art style is very tight and well directed, the music is fiiiiiire, and all in all, I had a good time!
Congrats on the game submission, and well done!