Nice little game!
This is a really unique take on the theme, and that goes a long way in a jam were I think there are a lot of overlapping ideas. Having such a simple mechanic works very well, especially when you use it a a majority of the levels.
Your level design is very good, every puzzle felt like a new way to use the mechanic, and I feel like I would've struggled myself to design many levels without having to introduce new mechanics. Each one added to the complexity, without jumping too much in difficulty. I'll admit that I didn't finish all of the levels, I got to the elevator ones, and was surprised that the game still had more content. This is a great amount of levels to have gotten out when you look at the polish of the rest of the game.
I do feel like the character movement can feel a bit weird. You seem to have some sort of grid snapping system, which I do appreciate, but you can also move freely. Because of the grid snap, I'd often try to just tap a direction and expected to just move one cell, and I wish that that could be a feature on top of being able to move freely.
There is also some (maybe intended) things that you can do with the loops that feel a bit weird, like on some levels you can slide on walls when holding onto a loop, and functionally make it smaller or bigger.
I was going to say that the music was rather repetitive at first, but then it kicked in on the first puzzle with a loop. I don't know if I just got really lucky with the timing, or you actually have dynamic music that kicks in once you use the main mechanic, and if you did bravo to you!
I'm also not sure if you ever tried to use them, but the WASD keys didn't work for me to move around.
I love seeing all the different Godot rep within this game jam, and I like seeing that this sort of style works really well within it!
With some extra mechanics, I could see this becoming a simple released puzzle game.
Nice work!