Valve’s critical hit Portal is now free for all. It had previously gone free alongside the launch of Steam on Mac last year but now it seems the new price tag is here to stay.
For those who have been living in a cave the past few years Portal is a puzzle game in which you utilise wormhole-like portals to complete various task chambers. It’s only a few hours long so pretty quick to get through. If you wish to extend your play there are various player-made maps around the net.