Don’t forget that Steam does weekend sales and this one will be over today. Here’s the official post from Steam:

The first person survival horror games, Penumbra Overture and Penumbra Black Plague Gold Edition are on sale this weekend for 75% off. Save even more and get both games together in the Penumbra Collector Pack.

Emphasizing survival and problem solving, these games utilize physics for deep environmental interaction, challenging puzzles and hidden secrets about the past of intrepid explorer Philip.

“Black Plague actually made me scream aloud in fright at one point. Even horror movies don’t have that effect on me anymore.” – PC GAMER [July 2008, p.68]