The story picks up many years after the events of the original Portal. The sequel plays out over nine chapters and builds upon the physics-based puzzles of the first game by including a variety of new gameplay mechanics, such as laser beams that can be redirected by special cubes, zero-gravity funnels that can be redirected by portals, launch pads, and paint-like substances that change the properties of the surface it covers. Portal 2 is a first-person puzzle game developed by Valve and published by Valve (for PC, Mac, and Linux via Steam) and Electronic Arts (via retail) it was released on April 19th, 2011. Overview Chell returns as the game's protagonist.