Blackgrove Manor is ddaazzaa's first mission, and it's a fairly ambitious one, at least in scale. The player is hitting an abandoned manor that is quite large, and fairly typical horror game things ensue. This is not to say it is bland or predictable by any means, and people who enjoy locations with creepy atmosphere and occasional jump scares will probably love it. The story is a little thin, but what's there is well crafted. Gameplay is the weakpoint of the mission and boils down to hunting for loot, keys and combinations. It's hard to fault it too much in this regard since narrative driven maps tend to be forced down this route. It only seems extra obvious in this case since the physical threat to the player throughout the manor is minimal (certainly not the mental threat though).
In conclusion I would recommend this mission to horror fans, but if you're looking for a challenge or more typical gameplay you're better off looking elsewhere.