As a musician and pianist who dabbles in jazz (and who also made a music game) I got a real kick out of this. Nice little backing tracks and a really funny story. I love that the evil piano player gets a happy ending after straight-up murdering a man in the venue. The dialogue and note made me wonder if you could make some sort of music mystery game with this concept…
It was very disconcerting trying to play using the keyboard keys - I kept forgetting what did what, and it was very cramped. But it works well enough for the game, which I think could be a fun educational tool. I teach piano lessons to young children and this reminded me of the silly game we let them play :) If you added some more mechanics and a more in-depth exploration of some of these musical concepts, I think you could take it a lot further. As of now it’s fun, but mostly just shows you a few scales in order. (Note names would be a good start! So would exploring some different styles of jazz.) I also agree with Oli that MIDI integration could make it a lot smoother. I’d love to play this with a real keyboard.
Anyway, this got a smile out of me. Nice work!
*Note: I’m actually glad you didn’t get a scoring system in because I don’t think there’s any way you could judge an improvisation that would feel fair.