There was just a desire amongst their staff to have a go with the series, and so it was that work began. But, revealed two of Valve's lead writers, Chet Faliszek and Erik Wolpaw, there were 150 people at Valve who hadn't worked on a Portal game and wanted to. The short game wrapped up perfectly, was wrapped up in its own legend, and things felt done. Why make a sequel to Portal is a good question. At various points, those were all things that could have hapened, as revealed by Valve last night in San Francisco. With competitive multiplayer and quantum co-op.
Imagine a Portal 2 with no GLaDOS, Chell, nor portals.
