Once upon a time, Final Fantasy: The Spirits Within was this amazing demonstration of what could be done with CGI. It's not so polished now that we look back at it, but during the time of its release it was quite the feat. The story though was terribly confusing with a mish-mash of different elements we've seen in the Final Fantasy games like environmentalism, communing with the spirits, Gaea and all that fun stuff.
So I guess it was only a matter of time before CinemaSins would get their hands on it. And the result was a quite suitable for what had come before.