UROBOROS!!! UHAHAHAHAH!
The idea is original, although I honestly didn't like the puzzles very much, but since I'm criticizing, I have to suggest something, for example, you could add a screen loop for the snake to the game, this would expand the possibilities of level design. You could also play with the idea that there is not one snake, but two, but they move on the same buttons with different controls. But these are just ideas, if you continue to make the game. Still, puzzles always take more time, since they require a lot of time for experiments.
By the way, why didn't you make the game available in the browser? I work in Godot myself and adding a browser version is not difficult. This is not a nitpick, I'm really interested, I just had a case when I used one plugin, and it was written in C#, so I could not build the project.
The game is not bad, although the levels are not finished. Thanks for the game!
Good luck in your endeavors!