First thing's first- I can't believe a single person made this in 4 days. Hats off to you! I love these sorts of games where I'm the guardian of predictable AI entities and I have to control them through indirect means. Playing with a level editor that makes pretty sounds is both unique and rewarding, and hearing my compositions layer on top of each other as I ascended was a fantastic feeling and a perfect example of what makes the interactive medium so uniquely powerful. My only constructive feedback is that the layout of keys felt unintuitive on some layers of the tower and broke the illusion that I was playing piano keys. One example that comes to mind was when the 'A' key served as the note one step above the 'M' key. It was an extra layer of mental gymnastics that made certain floors trickier than they needed to be. Because the game never requires use of more than one octave at a time, I think the keys used could have been consistent across all floors in an unbroken left-to-right layout, similar to a piano. But don't get it twisted- this game rocks and my singular gripe didn't hamper my enjoyment. Outstanding work, and you can bet I'll be checking out your future projects!