View full game: Bloody Walls
This add-on does have NPC's, "find an item" tasks and inventory management.
All you have are some bottles of antidote and some entry-level weapon sets you can choose from.
You fill confront some serious undead forces. Each level is a battle with a mini-boss and his minions.
The DLC contains:
All DLCs: Bloody Walls
Hardcore x2 Extended version