This is a great interpretation of the theme! This game has excellent sound design, and I love how the visuals are very simple to keep the sound the main focus.
I think the one thing this game needs is a little more clarity. I was able to figure out how to use the instruments except for the piano, which is troublesome since it's the first one. Level 2 I passed both last night and today while testing and I never figured out why the piano unlocked the door. I just mashed and eventually it worked.
Awesome job!
Viewing post in Echo Waves jam comments
No worries my friend, puzzle games are the hardest for jams since they're so difficult to playtest!
I would suggest changing level 2 to a series of rooms, with the first few having a single piano in, and then the final room can be two pianos. I think that would make it much easier to teach the player what they do, because right now you don't get any feedback unless both pianos are on the right key.