I've never actually played FFVII. I know, blasphemy, right? But it's impossible to live on the Internet and not know these characters, and the animation looked so pretty, how could I resist?
(This review contains spoilers for the FFVII game, but not the actual movie.)
STORY - I recall looking up FFVII's backstory and plot once or twice on Wikipedia, but most of what I know is based on sniplets of casual conversation, fanart, random other things on the Internet, and the (bastardized) versions of the characters' stories in Kingdom Hearts. That said, Advent Children's story was mostly "Wait, what?" to me. Even for movies based off other media, it's always best to have enough cohesiveness for it to make sense to newcomers and strangers to the original; to that end, Advent Children definitely failed. Explanations seemed abbreviated and choppy, and characters did little to clarify their intentions or motivations. At times, it seemed like they were trying too hard to connect it to the game, as if people didn't already know what it was based off of. (Seriously, how many flashbacks of dead Aerith do we need?) And despite that, I hear from the diehards that the movie's story connected poorly to the game anyway.
The sickness is poorly presented and explained; its cure similarly so. A good number of scenes also seemed like they were there for the sole purpose of fanservice, rather than actual story progression. The same could be said for the inclusion of many of the characters -- they served no real purpose, but I'm sure all the fanboys and girls in the audience were screaming their heads off, and that's what really seems to count with a movie like this.
CHARACTER - Poorly developed, all of them! If they were even developed at all! Cloud seemed like he spoke no more than five sentences for the entire movie, and none of them were particularly insightful or informative. Why was he doing anything he was doing? Got me. Because he felt guilty? Because he felt obliged? Because he had nothing else to do? Most of his support characters were either mindlessly cheerful or vacantly stoic; none seemed to have any real depth. The children, as well, did not seem to have any substance -- they were mostly objects to be protected or to be captured and mind-controlled. They weren't people at all.
Reno and Rude provided some humorous antics and were entertaining to watch, but beyond that, it's the same thing for the most part. I suppose they have the excuse of working for an organization for their motivation, but we never really see anything beyond that simple exterior. Kadaj and his brothers were just the same -- one-dimensional characters with tunnel vision. What exactly they were trying to accomplish always remained vague, and why exactly did Kadaj manifest as Sephiroth when he came into contact with Jenova? Well, shit, I don't know, but it's probably just to give Sephy some screentime because otherwise he's dead, right? The entire movie was built around that final fight. There is no other greater purpose or story. Advent Children is a 100% fanservice movie.
ARTSTYLE & ANIMATION - Now, this is where all my harsh words end, pretty much. The animation was beautiful. Beautiful! Stunning! The details in all the renders -- backgrounds, characters, clothing, weapons... everything was gorgeous, moved smoothly, and integrated well with its surroundings. The special effects were great, too. This movie is full of so much eye candy, your brain will explode. Even the simple things, like the inverted forest, or our five minute long scene of a cell phone falling through water -- all of it looked beautiful. I mean, come on, things have to look pretty darn amazing for me to be entertained by a falling cell phone for that long.
MUSIC - Another flawless aspect of this movie is the music. From the very first track, I was completely in love with Advent Children's score. A collection of different composers did the music for the movie and each and every one of them did an absolutely amazing job with every single track on this soundtrack. Every melody fit its scene, and every scene was so much more emotional or exciting because of it. The piano thrashing for "Those Who Fight" makes me wish I could play better. The guitars in "Black Water" get me totally pumped every single time. This soundtrack is also definitely one you could listen to over and over again, independent of the movie, and I'm sure that many others who haven't even seen the movie could enjoy the music here. The vocal track, "CALLING," at the end of the movie is also pretty nice, and I thought it was a great way to conclude it all.
VOICE ACTING - I've seen both the sub and dub. The sub was amazing. All the voices fit their roles wonderfully. Kadaj and Reno in particular had very memorable performances. The dub was much better than I thought it would be; really, the only real problem with the dub is Cid's hick accent, Yuffie's annoying voice, and the fact that Tifa's "zuruzuru zuruzuru" definitely did not translate well because we silly English-speakers don't have a sound effect for "dragging." Other than that, I couldn't have wanted more from the dub. An identical voice cast was used for all the FFVII characters in Kingdom Hearts II, so the voices were familiar. This also impressed me since the same was true for the Japanese version. What impressed me further was the fact that both Reno and Axel were voiced by the same actor in Japanese, and the same is true in English (ironically for Axel, his voice is also the Human Torch). Those little similarities are what make the fangirls happy. Moving on though, Steve Blum as Vincent Valentine? Totally awesome.
OVERALL - I think it's the general consensus all across the board that no one watched this movie for its brilliant storytelling and character development. This was an eyecandy movie for fans to squeal over. Really, the best way to watch this might be in Japanese with the subtitles off. That way, you can play ignorant to the bad stuff, but you still get all the brilliance of the voice acting, all of the amazing music, and of course, all of the visual madness that is this Advent Children. Enjoy.