It's frickin incredible. It's basically a 2 hour long cutscene of a Final Fantasy 7 game, rather than a full hollywood-style "movie". A little bit of animation looks stiff and the camera work is a little uninspired in some places, but not many. The music was actually composed by Nobou Uematsu, and while great, classic, and catchy, it still sounded like he was using the PSOne instrument set. The quality of the video definitely clashes with the quality of the audio.
But yeah, the fight scenes are absolutely mindblowing - like every strike in every scene is well thought out and "slick" in some way or another. While watching it, I could see that this is how the director had always envisioned what FF 7 was/would look like, but was held back by the PSOne and "interactivity".
The movie, for what it is and what its trying to do, is definitely the slickest piece of CG I've ever seen. Just don't expect a "movie", instead enjoy a non-interactive 2 hour long Final Fantasy cutscene which happens to be very, very good.
Highly highly recommended.