Paradox has released a
demo for their upcoming horror/puzzle game
Penumbra: Black Plague. The 137 MB download includes the first four levels of the game and should give you a good taste of the what the game is all about. I've been playing an early beta of the game and it's not bad but not very good. The puzzles are very much a trial and error approach with the error leading you to instant death. That said there are some cool concepts in the game as you really have to use items in the environment to solve the puzzles and the game has an "insane" meter that's a little reminiscent of the system used in
Eternal Darkness (not that the game is that good).