What We'd Like to See in the Next Portal

Warning: This editorial contains spoilers for Portal and Portal 2. If you haven't played those games yet, you should download them instead of reading this anyway. Portal 2 doesn't need a sequel, and I wouldn't even want a Portal 3. Making a sequel that's able to compete with the nearly perfect original Portal was already a nearly impossible task as the game's writers discussed during 2012's Game Developer's Conference. And chances are, Valve still has no plans to jump directly into another Porta...