 The March 2010 announcement said that Portal 2 would be released in late 2010 . In August 2010 , Valve postponed the release to February 2011 , with a Steam release date of February 9 , to allow it to complete changes to the game 's dialogue , to fill and connect about sixty test chambers , and to finish refinements to the gel gameplay mechanic . Valve announced a further delay in November 2010 , and gave a worldwide release date through retail and online channels of April 18 , 2011 . Wolpaw stated that this eight @-@ week delay was used to expand the game 's content before reaching an internal milestone called a " content lock " , after which no further content could be added . The remaining development work involved debugging . Newell allowed the delay considering the added benefits of the new content , because he thought the company would not lose any commercial opportunities because of it . On February 18 , 2011 , Newell confirmed that Valve had completed the development work on Portal 2 and that they were " waiting for final approvals and to get the discs manufactured " . Portal 2 was the first Valve product simultaneously released for Microsoft Windows and Mac OS X computers through the Steam platform . Retail copies for all platforms were distributed by Electronic Arts . 
