The characters are beautiful tragedies, not the least of which is Mercy herself. The artwork has a magnificently melancholy quality about it. The writing is sharp and witty.
But for love of the gods, pick something else besides the arrow keys for the rhythm game. Having the arrows pointing every which direction, but the actual prompts lined up horizontally, is brain-breaking. I'd recommend A-S-D-F simply for ease of use - most gamers are already comfortable having their hand in that position on the keyboard, anyway, and it allows easier simultaneous use of the mouse & spacebar (the two primary ways of navigating through a Ren'Py novel).
There's something amazing and special here, but it definitely needs a bit of refinement. Looking forward to more!