The long wait is over as Portal 2 is released on PC, Xbox 360, PS3 and many others. Portal 2 is a first-person action/puzzle video game, developed by Valve Corporation. It is the sequel to the critically-acclaimed 2007 video game Portal and was announced on March 5, 2010, following a week-long alternate reality game based on new patches to the original game. Play it here.
Portal 2 walkthrough
Co-op Level 5-8 (Last Level) & Ending Scene