I thought it was okay. I was pleasantly surprised. I'd been expecting to be bored, this being Ghost in the Shell and also just the spin-off movie of a TV series. However it will have helped that I'd last watched Ishii's 2004 sequel, Innocence. (It's not hard to be more entertaining than that.) Those caveats aside, though, I got through this fine. I even considered watching its parent TV series, which I hadn't been expecting at all.
I'll start by explaining where this film comes from.
1989 = Masamune Shirow creates the original manga
1995 = Mamoru Oshii turns it into one of the most famous anime movies ever made, although he makes some big changes
2002 = an anime TV series appears, called Stand Alone Complex. This is a new continuity, independent of both Shirow's manga and Oshii's movie.
2004 = it gets a second season, while at the same time Oshii releases Innocence.
2006 = Stand Alone Complex gets its own spin-off movie, called Solid State Society and set two years after the end of the TV series. Hence the cumbersome three-part portmanteau name. (Technically there are three movie-like things based on Stand Alone Complex, but the other two are compilation movies.)
There's since also been the Arise continuity (2013-2016) and the Hollywood remake (2017), but ignore those for now.
Anyway, what's different about this film is that it's a police procedural. The film's actually about the investigation. The process of identifying criminals isn't just a framework for action and/or philosophising, but the whole point of the movie. Public Security Section 9 is investigating some terrorist suicides. That doesn't mean suicide bombings, but actual suicides. People are putting guns to their heads and pulling the triggers. Now some of these terrorists had been in the process of planning more terrorism, so you might reasonably argue that their self-destruction isn't necessarily a bad thing. However one should probably try to understand any string of mysterious violent deaths, especially in a world where hackers can do almost anything to your memory and perceptions.
The film doesn't have much action, but I'm fine with that. The action quotient's about right, as far as I'm concerned.
It has a reasonable amount of dialogue, but the good news is that it's all relevant. Investigators are investigating. Sounds fair enough to me. This is a process of analysis and deduction, so one should expect dialogue. What's more, they're all saying things that a reasonable investigator would say, instead of drifting away on their own verbosity and being Oshii-esque. I think they're mostly human. Major Kusanagi quit two years ago and Batou likes going off on his own, so for the most part these cops are humans under Togusa. The usual Ghost in the Shell themes and preoccupations are still present in the plot, backstory and villains' motivations, but they're not being teased apart as much as you might have expected in the dialogue.
(NOTE: I wasn't making such comparisons when I reviewed Arise, which has even less philosophising, but that's because I hadn't seen any other Ghost in the Shell at the time.)
Its production values aren't as lavish as the Oshii movies, but it looks fine and I enjoyed the sense of a larger world. That's what a 52-episode TV series gives you. Section 9's investigators are a large, professional team of people I'd never seen before, who call Batou and Togusa "senior" and can call on spider robot tanks. These are Tachikoma. I'd been hoping they'd be funnier, to be honest, but I'm still glad to have them. (Are there any Tachikoma-heavy episodes of the TV series? Hmmmm... yes, ep.41 and some comedy shorts called Tachikomatic Days.)
Is there anything here that's actually good, instead of just exceeding my expectations? (There's still not much characterisation, for instance. Section 9 are professionals who never even hint at the possibility of personal emotions or desires, with one exception.) Well, the plot involves children and there's one point where this becomes very strong indeed. You'll know it when you see it. That's the properly good bit of the Ghost in the Shell franchise, as far as I'm concerned. On another level, I like the unpredictability of this Kusanagi and how they weave that into the plot.
It's fine. It still has the problem of being Ghost in the Shell, but it's okay. It finds a way of getting personal, while at the same time being a decent cyber-police procedural. I like the politics, the ideas and the generational theme. You could do worse.