Penumbra is a first person horror adventure focusing on story, immersion and puzzle solving. Violence and combat is hardly an option - the player has to use wits to guide Philip through his final test, and this makes the series unique in offering a truly dangerous and terrifying experience.
I only played the demo but, I will tell you what I liked from it. The story was interesting, the puzzles was challenging, and through the demo, I was close to the screen waiting for something scary and when it did, I jumped. This a definite competitor to amnesia, great game!