Watching Final Fantasy is like watching somebody else play a video game. If that sounds apppealing, this movie is for you. It's also fun if you like playing spot-the-celebrity-voice-actor, but if you're any good at it you'll nail them all in the first fifteen minutes. The plot has a lot of mystical mumbo-jumbo about Earth spirits and the like, which I generally kind of like, but after a while it drags a little. Overall it leaves a similar impression to that of Team America (the puppet movie by the South Park guys): "Wow, what an amazing technical achievement! Bummer about the script."
It reminds me of a time I was in college, hanging out in somebody's dorm room and a this dude's roommate rented some anime spy thriller called Golgo 13 (a title with which I was familiar, coincidentally, from its tie-in Nintendo game). About two-thirds of the way through the movie as the plot was beginning to grow a bit tedious, my friend turns to his roommate and goes, "Hey, I just figured out how you can get your money's worth from this rental: if you squint at the screen just right, it sort of looks like a real movie."