Thank you for your feedback!
I agree with everything you said, except that personally and like some other people I really think the music suit the game because it put you in the shoes of the demon gourmet, you are doing horrible things (cooking people) in a super cheery way because you like cooking. The music doesn't fit the violence of the game because for the demon it's totally normal tossing people into ovens, and he likes it.
Other than that yes the UI seriously needs and update!