Valve promises this will be a busy week for trailers for 3 brand new games they will be releasing. First one being Portal, a first person puzzle game with…well, portals. Download the trailer and check out this unique puzzle game. To download the video, simply click VIDEOS at the top of this page, you must be a member of Gametactics.com (it’s free to join!).

Portal is a new type of single player game that changes how players approach, manipulate, and surmise the possibilities of any given environment in a manner similar to how the Gravity Gun changed our approach to how an object may be leveraged in any given situation.