From the first Volume 1 could tell this was a much better story than was presented in the Movie. Enhanced greatly not only by the amount of detail in the story and world, but also the incredible coloring done in the version I was reading by Steve Oliff. For the version I decided to read the Epic Comics version of the manga. While some might have issues with it being mirrored for a US audience, I found the coloring to add far more than reading it in the orignal form. And since Otomo was directly involved with the coloring and mirroring process, I don't really consider it a horrible sin or anything. And really incredible to read the story about the amount of work it was to color this manga.
Now onto the actual meat of the manga, the amount of extra content that was cut from the Movie is incredible. When I first watched the movie I was disappointed with how it progressed and what happened, but I feel I have a much better appreciation for the movie now that I have read the manga. It managed to compress a series of 2500 pages or so into a 2 hour movie. Now the manga really used this space to really build heavily on the world, characters, story, and lore of the world.
On the world building side, this really felt like it was a world experiencing massive changes and how many groups would grow from the destruction and changes occurring. Various factions working to embrace or escape appeared in the middle of the destruction, and they all had pretty well defined goals and reasonings behind their actions.
This applies nicely to the characters as well, with them all having a reason for their actions. Never did I feel like somebody was doing something that didn't make sense for them to do, it all just felt really natural. Even moments when the characters go crazy and insane, it makes sense based on what has been building and explained throughout the manga. They never had moments that I feel were out of place or completely out of place at all.
The story and how it built the lore of the world came together very nicely in something that feels satisfying. The powers that exist all make sense in the end, and things wrap up nicely into a package is rather neat. Some points I feel did get a bit rough, but that could also be me missing something while reading. Some I wish had gotten more development was the international reaction to what was happening. Some occurs at around the halfway point, but it is pretty much limited to a single faction that plays an incredible major role in the rest of the story and the occasional mention of the UN or scientific groups. But overall it kinda feels like the rest of the world wasn't really watching or worrying about what was occurring in the city.
One thing I didn't really care for though was the ending of the manga. It felt kinda odd to me that this is the choice that would be made, after all the destruction and ruin occurred. Sure you can show respect and care about the people who ended up being lost, but they really took an extreme reaction I feel that isn't going to end well. Why take a move that will cause more fighting and death after what occurred, instead of working toward peace and cooperation.
Overall by the end of this rather massive manga, I am really impressed by what I read. Thanks to the coloring it looked like something far different than I've really seen in other manga. Appearing more like a comic or graphic novel really than a manga. If you even enjoyed the movie a slight bit, I fully encourage reading the manga, just best of luck tracking down a legal version of the Epic Comics version.