One episode suggests that to become a great designer you must learn to play like a designer. You must participate in the experience while simultaneously examining how the game manipulates you. Examine how the combination of mechanics, aesthetics, or anything else caused some emotional reaction. This is really hard to do because the act of observation often taints your enjoyment.
In practice it's much easier to do this for bad games, or at least obviously flawed ones. When something feels off it pulls you out of the moment. It's relatively simple then to write a list of all the problems which made the experience run aground. No matter how polished, most games will have these moments.
