Penumbra

In Penumbra the player finds himself in an underground base on Greenland, searching for his lost father. It's an adventure horror game, free from classic first person shooter elements, with an emphasise on puzzle solving and exploring. Constantly on your toes you will never know what to expect, with no weapons how do you protect yourself?
LINK 2 including torrent  from creators of the game.

REQUIREMENTS: CPU 1000 MHz, 256 MB RAM, ATI Radeon 8500/NVIDIA GeForce 3, WIN 2000/ XP