Love seeing a pico-8 game, and nice rings! Beautifully rendered. This is a creative spin on the theme. The difficulty stayed flat for 20 levels so it got boring, but this could be a great start to a puzzle game if you continue work on it.
I'll look into the difficulty ramp. When I tested it, after 5 or 6 levels got interesting. Though, I agree it can still get boring, since I didn't have time to add any other mechanics than spinning the rings.
