To start off I'd like to remind everyone that this was not the full movie. They're not done making the full movie, this was simply a 30min preview of what they have done so far. Two Square Enix employees, one from Tokyo and one from LA, came to the screening promising that they're working on it as we speak and that it should be roughly 80mins when complete.
I'll try and keep this part as spoiler free as possible: The animation was stunning, just gorgeous. The attention to detail is fantastic. Even the most miniscule thing, like the ring on Clouds suit clinking and moving, are what made the animation for me.
Square has come a long way. But even so, I found much less detail was put into the background characters. While the main characters, such as Cloud and Kadaj, we stunning and one could barely tell they weren't real people, other random back round characters it was painfully obvious they were in fact CGIs. Overall, it was beautiful.
For those of you who have managed to not hear about this already, here's a quick plot summary. Two years after the final battle with Sephiroth, things in Midgar are starting to return to normal after the trouble with Shinra. Unfortunately a new disease called "Geostigma" is affecting the citizens. With the appearance of Kadaj, and his brothers Yazoo and Loz, stirring up trouble searching for their "Mother", Cloud and his friends have more then enough to deal with.
SPOILERS, highlight to read
There aren't actually much to say in the way of spoilers. The first 10mins of the showing basically recapped the ending of the video game. Not exactly helpful to those who've never played the game, but a nice refresher to those who haven't played recently.
The plot really starts after Cloud calls Tifa. After hearing that Reno has a job for him, and promptly hanging up on Tifa, Cloud drives off on his shiny motorcycle only to be attacked by Kadaj. After managing to escape the brothers, Cloud appears before a figure in a wheel chair, draped in a blanket with Reno and Rude flanking him. He's asked to be hired as the man's body guard, being an ex-SOLDIER, the man feels he is the only one worth hiring. Cloud flat out refuses and leaves.
Meanwhile, Tifa discovers that Cloud is suffering from geostigma and has been hiding it. Just as she makes the discovery she's attacked by Yazoo. At the same time Reno, Rude and their employer are also attacked by Kadaj, who's demanding they help him in locating his "Mother".
Skipping many small details, Cloud finds that Denzel, who is also suffering from geostigma, has gone missing. Lured off by lackey's of Kadaj who promise to cure the boy. Cloud goes to fight Kadaj, only to find that he's essentially brain washed all the children he lured away. Luckily Vincent shows up to pull Cloud away from the battle before he does something he'll regret. There's a heart warming, thought provoking speech from Marlene to Cloud before the real fun begins.
The rest is pointless to summarize in detail. The last few minutes were simply a gorgeously rendered fight scene involving all the normal characters showing up to help out and creatures attacking the innocent citizens. Only point of note really is Sephiroth appears properly in the very last scene.
As a side note, it's not actually been confirmed that the person under the blanket, in the wheelchair, who has Reno and Rude working for him, is in fact Rufus. Though, due to the nature of end of the first cut and the simple facts, it's very likely that Rufus is indeed alive and well in this movie. Then again, Square could simply be messing with the fans.
In conclusion, Advent Children is to date the most gorgeously rendered CGI film I've seen. Even though I'm not a huge Final Fantasy fan, I will be waiting with baited breath to see the final version of this film.