Thank you for this kind words! You're right about graphics - it needs a lot of improvements. The buttons are default Godot controls and I hope to replace them completely. As for tiles - maybe some sort of normal mapping would work. Music is a free sample I found, it needs to be replaced too:)
How's the gameplay? What grid sizes you tried? I don't want to bother you with a lot of questions - just please share any thoughts if you have anything
Read the description again when you try bigger grids:) I was like "ok, I made it, I know how it works", but yesterday I got a challenge from a player (if you complete a pattern without hints you can get the challenge code and send it to friend so they will play the exact same layout but limited in time or moves based on your solution). I was devastated and spent almost a hour trying to solve that.