In Martian Gothic, the player is able to assume the roles of three characters sent from Earth to a Martian base called Vita 1 to examine why it has been silent for 10 months, after a base member broadcasts a final message of "Stay alone, stay alive."
http://www.gamespot.com/martian-gothic-unification/My input:
This one is from the times when horror games were actually horrifying and non-linear with a huge map to walk around in. I didn't complete all of it, actually I only made through like 2% of the game and that was it. Shit's too scary (at the time and would probably still be). Games become scary when they emerge you into the gameplay and then the cubic-looking game graphics doesn't matter (fuck yo HD graphics!).
So basically I liked this game a lot because of the non-linear gameplay and a scary storyline. Try it out!