Unfortunately the gameplay aspect seemed haphazard and the co-op aspect seemed like a last-minute addition without much thought to it.
The haphazard feeling came mainly from the key bindings, which was probably intended for a controller, but even then I feel like it'd be too many buttons to keep track of. Why not just have a weapon wheel and 1,2,3,4 for abilities? Instead pressing X for this, Y for this, Z for this, F for this, R for this, Q for this. Click 1 for this weapon, click 1 again to switch to this other weapon. It was confusing af to keep track of with the result that we ended up mostly using the same 2-3 things all the time because it was what we could each remember how to use.
And why we got the feeling that co-op was a last-minute addition? Because we were both playing the same dude. Only the host gets gameplay progression. And the game literally doesn't allow you to explore without the other person tagging along behind you.
For generic enemies the game went with the tactic that "more advanced means more HP" which in reality meant that higher tier enemies were supreme bullet sponges and tedious to fight.
Why does the game tell me what I missed in each chapter if it isn't going to let me go back and replay that chapter in an attempt to find what I missed?
The boss fights were all really cool, though! The fight against William especially. All of the boss fights required tactics and figuring out mechanics, which was a nice pace from "dodge when it charges and hit it when it doesn't".
The story was pretty generic as far as vampire stories go. Enslave humanity, blot out the sun. The usual. But the different varieties of vampires and how they were made were really interesting. Some of them were very wtf.
I got a bug towards the end where every time I opened the skill perk menu the game sound would vanish and when I exited the skill perk menu the game would lag and stutter considerably until it simply crashed to main menu, where I still had no game sound. I needed to restart the entire game to get game sound back, and yet the same thing would happen every time I opened the skill perk menu. To the point where I didn't dare to assign my new perks until we were safely behind an autosave. Because there's only autosave, you can't save manually at all.
So all in all, amazing vibes, poor execution.