Portal on Steam

September 16 2011, 1:10pm

Portal on SteamSource: store.steampowered.comPortal™ is a new single player game from Valve. Set in the mysterious Aperture Science Laboratories, Portal has been called one of the most innovative new games on the horizon and will offer gamers hours of unique gameplay.    Portal™ is a new single player game from Valve. Set in the mysterious Aperture Science Laboratories, Portal has been called one of the most innovative new games on the horizon and will offer gamers hours of unique gameplay.