A new mod for Half-Life 2: Episode 2 was released not long ago. It is called Nightmare House 2 (
http://nh2.wecreatestuff.com/ ). I just finished playing this mod and in my opinion it is better as horror game than Penumbra Overture or Black Plague and this is why:
-More and better encounters
-More kinds of enemies
-More enemies in levels
-Much less loading screens
-More "WTF???" moments
I think Frictional Games did a great job in making a great horror game but I think they should try out this mod for inspiration sometime. I believe you can find some references in that mod related to Penumbra.
I would like to know what do you guys think about this mod?