You play a "hunter" in a world that's dark gothic horror mixed with lovecraft.. Blood can be used to make powerful healing medicines.. and many people have become afflicted with blood diseases that transform them into Beasts, which are the creatures you're hunting..
There's a lot of exploration and retreading areas, trying to find the best way to survive your way through them.. In souls games, if you kill a friendly NPC, they tend to stay dead.. same with bosses.. Normal monsters revive themselves every time you stop at a resting point (usually marked by lamps) and recover your health.. You there's a leveling system and you gain experience points for killing monsters.. The combat can be difficult at times, you can use bells to summon other players to help you fight though.. (I think this comes at a risk of allowing hostile players entering your world to fight you.. it's been a while so I might be mistaken on that..)