There's a number of issues I have with this movie but let's start with the first. Solid State Society is basically a Ghost in the Shell "greatest hits" of sorts. The movie combines aspects of the 1995 movie, Innocence, and the first season of SAC. The 1995 movie in that the antagonist is called the "Puppeteer"(not Pupper Master) who seems to be an all knowing AI. Innocence with the kidnapped children and Motoko Kusanagi leaving Section 9. The first season of SAC in that the "Puppeteer" is a also a hacker along with sort of being an AI. It also has the visuals and music of SAC. My problem with this is that this movie doesn't really have any original ideas of it's own, and as a result feels like someone got a collection of past GITS concepts and rolled them into one movie. The live action movie would funnily enough make the same mistakes to a much greater degree but that is besides the point. I just find it strange that Kamiyama would even do something like this considering the fact that SAC S1 and 2nd Gig do a great job at breathing new life into GITS. Now it feels like he is apping off Oshii and himself.
Now the second issue, the fact that the movie timeskips two years after 2nd Gig and as a result, characters are changed in ways that don't feel natural or just feel like...and I hate using this term, "character rewrites". To name examples, Motoko becomes disillusioned with Section 9 and conducts her own investigations, Togusa is the leader of Section 9, the Fujikomas are incompetent, Aramaki is worried about Section 9's future, Togusa becomes cyberized, Batou only getting involved in cases that he finds interesting, Section 9 is greatly expanded on and Saito taking overseas ops. What do all these have in common? There is no smooth transition to any of these things, the only thing that links all these events together is nothing. By the end of 2nd Gig, it felt like Section 9 was still normal and nothing too bad has happened but get to this movie, and so much has happened inbetween the ending of 2nd Gig and this movie that I almost want an anime series or movie taking place during the timskip just to see how all this stuff managed to take place. This is why I strongly dislike timeskips in fiction and especially timeskips that gloss over major character development, and this movie did very little to change my mind on the idea. The scene where Aramaki and Batou might be one of the better scenes in the movie but the problem is that it's hard for me to care because I am not even what where all the events leading up to the conversation.
The third issue is that the villlains are completely underwhelming. Mune and the Puppeteer are both the main villains of the story and while both their motivations involving the kidnapped children, Japan's decling birth rate, frail old people, killing important people in Japan's political landscape and rewriting children's memories are interesting on paper, they are presented in a dry way where the characters only reveal any kind of character before they are about to die or a big dramatic moment. Before that, they don't do a whole lot of anything, and just feel like the only actions they did that mattered was right before they died or the major dramatic part. That and the "Puppeteer" might as well be an AI if the movie was going to resort to the resolution that it did regarding the identity of that character.
There are some things about the movie that do prevent it from being completely unwatchable. Yoko Kanno's music is great and hearing Run Rabbit Junk was great. The action is also pretty good and the final action sequence with the cyborg tanks is pretty good due to the music and action working in tandem together. The ending with Motoko and Batou with the slowed down version of "take a little hand" playing in the background along with the conversation the two characters have was a touching way to close off the series, it provides more closure than 2nd Gig's ending does, despite 2nd Gig being way better overall.
Overall, I enjoyed Ghost in the Shell SAC and the first two movies a lot but this movie I found to be really boring. Every time I watch it, I always struggle to finish it due to badly presented the villians are, the timeskip, and how the movie rarely has good ideas of it's own. If you are a SAC fan, I say watch it for the score and action but prepare to be underwhelmed, if you just watch this as just a movie, skip it because you are getting very little entertainment value out of watching this.
