It was great! Game looks very nice and the music was great.
The clues (both visual and notes) were very good, I got the right combo on my first try in most level which is a testament to that. Plus with how the game works you can't really get stuck which should prevent having to look for a walkthrough.
Levels had good continuity, you could see where you came in from, nice touch.
The ending was great :)
Gameplay is a bit simple but it's good for this length, if expanded into a longer game would need to add more mechanics imo.