Portal 2, they went mad. It certainly appears that way now, when the final version of Portal 2 that shipped in 2011 was such a resounding success, especially for a highly anticipated sequel. The first iteration Wolpaw and Faliszek envisioned got rid of three important mechanics in the Portal universe: Chell, GLaDOS and, as we knew and are still reeling over, portals. In a talk at GDC, Wolpaw and Faliszek explained why they thought that was a good idea, and how they learned it was pretty much the dumbest thing ever.
The original Portal 2 had three new things in place of the classic ideas: F-stop (the new portal mechanic), Cave Johnson (antagonist replacement) and Betty (GLaDOS substitute). Betty was a knee-high personality sphere on wheels, a piece of concept art showed, and she spoke in quick legalese, "like those ads for medicine where they show puppies while they talk about the rectal bleeding you're going to have," Wolpaw said.