I liked the demo
I liked the visuals, I liked the combat, I liked the animations, I liked the voice acting. The music in the demo was just alright, the only gripe I can think of from my perspective.
It's okay if you don't like it. It's okay if you can't help but be a franchise purist. The fact of the matter is, we got over 30 Castlevania games by this point, and almost everyone involved with those games have moved on. We probably won't ever get a new Castlevania that will feel "quite right", but this game felt great to me, even if it can't clone the exact aspects of the best games in the series.
Nostalgia can have a powerful hold and heavily influence what we consider to be enjoyable, I get that. It's a sad thing, to me, because It has generally not been an issue for me, but It's something I've seen in other gamers time and time again.
In my opinion, it IS a pretty good game. The combat is punchy, the visuals are good enough to make me pause exploration just to oggle them repeatedly, the story is compelling.
I won't tell you to give it a chance, but there are going to be people that will really like it, for some of them this will be their first Castlevania, and that should sound like a good thing to you, because it means more fans of the series, and that's a good thing for every Castlevania fan.