The game has a visceral, impactful free-flow fighting system that emphasizes counter-attacks, dodges and stringing combos with a variety of weapons and moves.
The game has stealth sections that involve turning into a rat and getting from one place to another while avoiding detection, but the stealth gameplay is very barebones and feels very out of place in a Castlevania game.
Some aspects of the game are considerably different from the previous Shadow game. For example, combat is a lot more God of War than Castlevania and boss fights are a lot more Shadow of Colossus than Castlevania.
The role-playing elements of Vampyr are the strongest parts of the game. You're a vampire, so you need to feed on blood to survive through killing the various characters you meet. These NPCs are regular townspeople, questgivers, and so on. If you decide to get to know your target better through solving their problems and speaking with them, you earn more experience points once you finally do devour them. This also has the interesting effect of blocking off future story paths and possibly making your city less safe once certain characters are dead, giving some weight to your choices through long-lasting consequences.
The game's setting is very fitting for a horror story. Set in London during the years of World War I, the city is gritty, dreary, and full of despair, yet there are some bright spots, like the many flavors of characters you interact with. The time period also lines up with the outbreak of the Spanish flu, adding to how drab and creepy the city is. Buildings are run-down, the streets and alleys you pass through are dark and unsafe, and you can never be quite too sure if you can trust the people you run into. The atmosphere is really well-done here, with lots of detail and realism.
The breadth of characters you come across adds a lot to the atmosphere and culture. Since this is in London, you meet both highborn and lowborn NPCs, with certain accents and style of clothes to match their class and status. The people you decide to help through quests have all sorts of personal histories and secrets for you to learn about, adding to the dynamic of whether or not you decide to feed on them for your own survival. Vampyr's diverse characters adds more weight and intrigue to the role-playing aspects, making the game's story much more memorable.
The hack-and-slash style action combat leaves a lot to be desired. It's not terrible, but it's not good, either. When trying to lunge and attack enemies, there's a strange sensation of your attacks not quite connecting and your overall movements not really syncing up with your button inputs. It's pretty clunky and it lacks a cohesive flow, though there are some cool moments like grabbing opponents to feed off of their blood. If you don't mind how weird everything feels, you might find some enjoyment from the combat anyway.
The character animations in Vampyr aren't the best. The main protagonist's animations are okay, since they clearly had the most work put into them over the other NPCs. His combat moves lack weight, though, which is part of why the fighting doesn't really live up to much. For everyone else, their movements are stiff at best and wonky at worst, always looking unnatural or weird.
From time to time, you may run into some framerate dips and other stuttering problems. The unstable performance is made even worse by the autosaves that pop up and completely freeze the game for a few seconds. Even though these things don't happen that often, when they do occur, they're distracting enough to pull you out of the moment. They give the overall impression that the game is unpolished.