I have played the piano as a child so the concept was very familiar to me and I had sooo much fun playing the game. Absolutely astonishing. The only con I see is a minor bug - when hitting practice and hearing the result, if I think I have to change the order of the cats somehow, some of them are stuck where I put them first. I had to leave the level and restart it to refresh the cat-notation. This happened three times on different levels. But I loved the game beside that.