During the first Portal, players used their portal gun to solve puzzles and thwart enemies in an attempt to escape from the control of GLaDOS. Now with Portal 2, a brand new storyline and game play elements bring a whole slew of challenges to overcome. Valve Writer Erik Wolpaw talked with us to describe some of these new challenges. One of the differences Wolpaw describes is the change from using two portals to four, as well as the addition of a cooperative mode. Two players will now be able to run through the game using all four portals to solve the game's multiple puzzles. More game play changes include the "bridges" that players can create within the portals, the use of lasers, and finally, a new feature called "gel" which can paint over enemies and environments. Also, the single player experience is noted to be at least twice as long as in the original Portal. Valve's Portal 2 is slated for a April 19th, 2011 release on PC, Mac, Xbox 360 and Playstation 3. Host: David Klein Executive Producer: Spencer Striker Creative Director: Andrew Benninghoff Producer: Tyler Thompson, Thomas Schulenberg Graphics: Andrew Benninghoff, Andrew Von Haden