Portal: Still Alive (2008)

Portal: Still Alive is a retooled version of the original smash hit first-person puzzle game, with additional levels and challenges. As unwilling test subjects in a sinister laboratory, players must break the laws of physics using 'portal' technology to solve puzzles and survive. Featuring a darkly comic story that weaves adventure with brain-bending puzzles; 'Portal: Still Alive' also introduces 14 brand new bonus puzzles to challenge even the most skilled test subjects. Players can also get a glimpse into the making of 'Portal: Still Alive' with commentary from the developers.

• Release Date: October 22, 2008
• Developer: Valve