This is a really cool game! I love Guitar Hero and it was awesome seeing a take on that type of rhythm game. Buff lady is my favorite character. If you plan to continue working on the game, I should mention that I did notice a bug where hold notes sometimes would disappear before getting to them (this might have been caused by me pressing a previous note too late?). I also have some suggestions for if you want to continue this (I understand there's not a lot of room for polish in a game jam time):
• It would be cool to have more feedback when hitting a note! In Guitar Hero flames pop out and it's really fun
• In Guitar Hero, when you miss a note the guitar track cuts out and a broken string sound plays. I'm not sure if that specifically would make sense for your story since it seems like the guitar is imaginary, but maybe something similar to give the player more feedback when they miss a note?
(Spoilers) It was so sad to find out that Grombit was the killer. He's not a bad frog he just needs love :(