Lots of people I know hated this movie. For some, it was because the movie was too far a departure from the Final Fantasy series we know and love. For others, it was because the movie had a practically brain-fart of a plot with an ending that barely makes sense.
I loved it though. I loved how far CG animation had gotten in this movie. And how much this movie set a bar for the use of CG in visuals and humanoid texturing. A pity however that this movie would barely be remembered for that (and instead James Cameron's rip-off baby Avatar will).