Rewarding The Players: Valve On Portal 2 on Gamasutra has the entirety of a Portal 2 interview with Valve project manager Erik Johnson, which originally appeared in the October 2010 print issue of Game Developer Magazine. Topics include the complexity being added to the puzzling sequel, maintaining continuity with the first Portal, the return of GLaDOS, their interactive commentaries, revising writing during gameplay, offline versus online games, and more.