This was definitely one of my favorites of the jam! I really like how it balanced technical skill & puzzle solving skills, I love games like those because you get both the "aha" feeling of figuring out the solution and the satisfaction of successfully pulling it off.
Tying the loop to the rhythm of the music was a clever & effective idea at making sure the loop timer was easy and natural to figure out while playing. The main theme is also catchy and the motif is strong, it has a lot of flavor but definitely leans towards the side of repetition, but that also helps keep it playing into serving as an indicator for the loop timer. And it's a nice touch that all the cute lil' sprites are in rhythm to further drive that home!
Now as for the level design, this was obviously where the game needed to shine and it delivered. This is the type of premise that demands tightly designed levels that aren't feasible to achieve in a jam deadline, but what you did pull off is really impressive & quality for the amount of time you must've had. It took me quite a bit to fully grasp the loop mechanic and get used to it, but once I did the gameplay felt snappy & good to iterate through ideas in. I especially love how each level that's added to the loop forces you to re-evaluate how you approached & used the elements of the previous levels, without actually changing any level's layout.
I will say that the final level/set of levels didn't feel as creative or well thought out as the rest though, but aside from that, great game!