Thank you for the very thoughtful feedback! I think you’re exactly right about the difficulty spike; because the xor drawing is the central conceit, it deserved a little more thought about how it’s introduced.
I also agree with the warning sign; it was added early on and never refined as well as it needed to be, and there are a couple of patterns where it’s really needed but is missing entirely.
The rhythm game pattern went through the most revisions for difficulty, so I’m really glad to hear it worked!