I think part of the issue with mixed reviews is the slower, more methodical pace of the game. There are lots of NPCs to interact with, long conversations being possible. Lots of details to work out and investigate. It isn't a fast paced beat-em-up adventure with superpowers, as some may have expected. Not everyone enjoys a slower paced game like this.
I think the combat is quite good, lots of options in powers, ways to confront enemies. It has a strong Soulsian/bloodborn vibe to it. Different enemies are faster, stronger, have powers of their own, have resistances you need to be aware of.
I really like the game and I'm about 6 hours into it, with an apparent run-time of 25 hours (and that's skipping a lot of side-stuff). As an AA game from a developer with some big misses, I'd probably give the game 4 stars/80%.
It doesn't help that some reviews seem to be scoring based on a comparison between this and Vampire: Bloodlines, which is completely unfair IMHO. That's like scoring an open world RPG on it's comparison to Witcher 3. It doesn't matter how good it might be, it won't ever hold a candle to the masterpiece of its genre.
I wasn't sure I'd initially purchase it - based largely on the developers shaky previous titles - but one of the reviewers I trust the most - ACG - game it very high marks with only a couple of drawbacks.