Dear Valve, 'Portal 2' better be awesome. But no pressure.[ Wed, 8 Sep 2010 11:28:03 GMT ]Developers at Valve say they've never seen players respond to one of their games quite like they have 'Portal.' The space-manipulating puzzle game was loved and lauded the world over when it launched in 2007. Now the developers are hard at work on the sequel. And they know they've got a lot to live up to.