Games like the Penumbra series?

[m1dy]

I have played and beaten all 3 of the Penumbra games no more than a day or two after each of them were released. I'm a HUGE fan, I consider the Penumbra series to be my favorite games alongside System Shock 2 and Duke Nukem 3D (that's saying a lot, I'm very picky with games).

I'll cut to the chase now -- Penumbra has left me with an unending desire for an extremely scary first person game with brilliant puzzles, very similar to what Penumbra did so flawlessly. Which leads me to my question written in the thread subject: Does anyone know of any games very similar to Penumbra? Or at least comparable to Penumbra's all-around quality? It doesn't have to be exactly like it... but something that's first person, scary and has clever puzzles is more or less what I'm craving.

Thanks in advance to the community for the great suggestions that are sure to come and thank you Frictional Games for giving me a horror experience that I'll NEVER forget. I'm really looking forward to the game you guys are currently working on. :3