We are made to see patterns. Our brains will give something roughly human a lot of the benefit of the doubt.
We're also programmed to recognize specific human faces though, and when an animated character is really close to looking human, we greatly notice the parts of those faces that are not quite right, thus the uncanny valley, where we are totally cool with a stick figure but Final Fantasy characters give us the heeby jeebies.
Anyway, very in depth, great entry!
Thanks for reading! never thought about it that way, but you do make a point. I like to play these kind of games and it does cause some kind of weird reaction, like those heeby jeebies you mention, because they're quite similar but not quite as well.