Really great and chill puzzler! I like how you went the extra mile and didn't just make the game, but made all sorts of little touches to it like having the game highlight mistakes (with an option to turn it off for a challenge) and a whole note-taking system: really impressive! I had a lot of fun going through the levels. It did have a weird bit of a difficulty jump at the beginning: level 3 got super hard outta nowhere (well, at least for me) and I felt like they could've been one more level between 2-3 and another between 3-4 to let the basic levels breathe and escalate before moving onto the sum levels. But heck, I had fun anyway, so nice work!