Nice concept - the art style in the cover picture drew me in to wanting to give this a try! At first I was wondering how on earth I'd manage to defeat all the enemies in a single run, but then I noticed the ghosts of my previous runs and it all clicked, that was a cool moment. I don't think I quite managed to clear all of the enemies in the end but I had fun.
My only feedback is that I found it hard to avoid the gunfire of the enemies sometimes and got shot from behind quite often - of course part of the game is discoverability and the puzzle of stacking your runs together in ways that compliment each other, I just wish there was more I could do as a player to counter this. Perhaps I just need to git gud. Overall, well done!