It's a decent family flick, if that's what it is, it has nazi's, gay humour, endless play on words, I'm not sure it's a kids film. But there's nothing objectionable to it, there's just nothing special about it either.
Such a massive miss on 50%, I won't say why until a bit down incase anyone mistakenly sees it, but the first two were great in that teenage 90s slasher style. Which is what the second half of this film was, it's even called Part Two in the film. That last third of the movie was really good. So one of two things must have happened:
1) They shot the ending, realized it was 40 minutes long, and reshot an hour tying in the flashbacks together to make a part one and couldn't figure out how to edit it properly, ran into a release deadline and it came out this way
2) Decided they really wanted to focus on a socio-political angle, and went hard at it, taking 2/3 of a 2 hour film to say "the "good people" are secretly cheating and lying, and have convinced the "bad side of town" it's their fault that things are the way it is for them.
Either way, that's the premise of 95% of stories, it's always the politician, the business, the "perfect" person that's bad behind the scenes, taking 70 minutes to tell that story in an out of place period segment destroys the flow of the movie series.
This was about as good as you're going to be able to do in a live action version of a dark, high concept story. I loved it, I went backwards from the anime movie, to the manga, to the live action, well not backwards, out of order, and thought this was really well done.