This is lovely!
The game is clearly polished and i already went through it three times.
The enemies feel a bit out of place though, but that’s the nature of a jam game. What i mean is, once you kill the enemies, the gameplay is back to being tone pillars only. However i love the addition of the ability to shoot pillars on level 6! What you could do is make the enemies feel more integrated.
Maybe killing a specific type of enemy activates the pillar next to it? Maybe the note gun gives knockback to you, which players can use for faster travel on earlier levels? Just some food for thought and improvement!