Great atmosphere, the start made me very invested and i loved the soundtrack, but, I have some feedback.
The gameplay itself wasn't very engaging, as i didn't really feel the weight of my choices. An idea may be to have some text or the like that show how the choices changes you, apart from just the meters at the top.
Though the smallest change that could make the biggest difference in my opinion would be to remove the information of what each choice does. I may have misunderstood the point of the game, but if it is to upphold the deal you made at the beginning, then the game may benefit from some ambiguity in your choices, as this would make upholding it a little harder.
That being said i think art, writing, music, and overall athmosphere of the game is great. I think this can be a very good game with some improvement to gameplay. I REALLY liked the writing, loved it. Good luck!
( I also had a bug when playing in fullscreen in the browser, where the devil dude apeared outside his box.)