Before i review I'll give you a little context - I'm a person whos a fan of final fantasy, but has not played FF7. I know enough about ff7 to get the general idea of the storyline before seeing the movie. Out of the population on this forum, I'm probably one of the members closer to what non fans will think on the movie. Also, i hadn't watched any of the leaked footage on the internet or seen what the japanese voices are like. I've only watched the film once, so my opinions may change in the future as i get to know the storyline better. There will be unmarked spoilers.
My opinion on the film is that it is interesting, visually appealing and made with beautiful graphics. They have conquered the fine line, where the characters look realistic, but do justice to their anime style character designs. They look real enough so that you think you could touch them, but pretty enough to hold the visual interest of the fans. Though the lip synching is occasionly off, the voice actors do a great job in matching it well (considering that Japanese also speak in different rythms to english, they seem to pause oddly mid sentence etc). The english voice actors have also been chosen well except for a few exceptions. Cloud speaks with a soft understatement, which is nice considering they could have chosen a 'tough guy' voice which wouldn't have suited the point at all. Perhaps the voices that don't suit their characters are that of Kadaj, Loz and Red XIII. The setting is crazily detailed and natural materials such as leather and water have been mastered outstandingly. The 'fiend' designs are especially impressive, as they look like they could harm the characters and also that they do come from that world. The ending, with the rain and the dissapearance of Kadaj, was beautiful and had me 'oooo, ahhhing' at the visual effects.
Advent Children will fall down for broad audiences, and maybe even fan audiences, because of three main factors.
Firstly, this does not feel like a film, but one looooooooong fmv. Though they have done very well, Nomura and his team show their lack of experience in feature films when it comes to pacing. Though they control the beginning well, after a while they approach every scene like it is a FMV - FMV's are mostly used to either introduce a character, to show setting or to show an action scene in a very fast and condensed minute. Too much is happening visually, as if they need to cram it in before the 'game disk runs out of space'. I can't really explain thoroughly what i mean, but if you watch the film again and think about the differences between an FMV and a movie, you will see how Advent Children is more like an FMV than a movie. Also, though they pick some outstanding pieces of music in some areas, in other areas they pick the completely wrong music.
The second problem is character development. We don't get very much. Obviously, fans will care about these characters even before they watch the film from already existing material (FF7 games). But the movie doesn't push anyone but Cloud forward here. The bad guys are not well developed. Kadaj and Loz do get some minor development, and are interesting in those moments (best quote: NO! I am not crying), but we just don't know enough about them to feel threatened. The smaller, long haired man (Yazoo) in the trio gets no development at all. These three are simply eye candy - they appeal visually and lead the way for a reason for the Sephiroth to make his appearance.
Thirdly their are too many action sequences, which probably ties into the above point. Some of the scenes 'worked', but others were too over the top, too fast. Sometimes it gets too over the top, and takes away from the beauty of previous scenes or the total assault on your eyeballs makes it hard to absorb what is going on. On one side, it will make things interesting a second time as their will be more I didn't notice, but on the other side in the long run it would have been better if they had kept control.
As a final thing, I'm glad Sephiroth appeared in the movie. I'm not even a fan, but near the end i started thinking 'he is going to appear, isn't he?'. I'm glad he didn't come back in actuality, but through another person (Kadaj). Its made me realise the appeal of Sephiroth - and that is anticipation and mystery. The character has an aura that inspires interest. On the flipside, and a complaint of many non sephiroth fans, his writing is not that great. Sephiroth is more a villian of visual appeal and 'legend', rather than substance. His parting words were good though.
I give it a 6.5/10