i really enjoy playing thru this, its got some nice exercises, and helps me keep my mind sharp in noticing differences.
I've got a new idea for a game mode
Unknown Forces Mode
Description: Muscle memory, that's all you can rely on, the info you need to verify who the doppelgangers are is present for a time, but then when you least expect it, it begins to constantly be manipulated by unknown forces at random times, shifting, editing itself, blurring, and sometimes disappearing entirely for a few moments. make a mistake and surrender to the unpleasant consequences of failure.