the animation is clearly bad, not hand animated like cuphead
the gameplay is a straight rip in every regard, they flat out changed nothing
and most of the actual boss fights seem too similar to cuphead fights
that being said I do like some of the things conceptually, the fight against beethoven trying to listen to you in the piano, the alien cow who is jokingly the offspring of a normal cow and an alien, and the transition from some seemingly weak dog into cerberus with the demons in the back cheering them on.
I don't think i've ever seen anyone both almost completely rip something off and yet also try at the same time, they really should have tried to do their own thing.