Portal is a single-player first-person puzzle-platform video game developed by Valve.Now is free download until September 20th for Windows and Mac users.
Portal has been called one of the most innovative new games on the horizon and will offer gamers hours of unique gameplay.
The game is designed to change the way players approach, manipulate, and surmise the possibilities in a given environment; similar to how Half-Life® 2’s Gravity Gun innovated new ways to leverage an object in any given situation.
Players must solve physical puzzles and challenges by opening portals to maneuvering objects, and themselves, through space.
First of all,you need to install Steam installer into your PC (Windows or Mac OS),then create your Steam account using steam installer ( if you don’t have any steam account ).
Go to Below Portal games web page and click ‘INSTALL GAME’ icon start downloading the game.