I see this movie getting absolutely crushed by the critics, but have to say my son and I enjoyed it for what it is - a kids action movie. You really can't watch a movie like this with any notion of a critical eye for plot, particularly with regard to continuity to the overall story. I know that doesn't seem like much to ask, but it certainly seems to be the case these days that they spend 99% of the budget on actors and special effects/CGI, leaving a few pennies for the writers.
Some non-spoiler takeaways, all of which are plagiarized to one degree or another from others:
1. The Dumbledore - Grindewald love story has fully emerged from the realm of rumor and is now firmly established as Harry Potter cannon. As this is supposed to run for 3 more movies, 5 total, it will be interesting to see how the world reacts to the flashbacks of their courtship, romance and sexual relationship.
2. In retrospect, it seems undeniable Dumbledore made a poor choice when he ditched the sporty tweed/flannel vested suits and neatly trimmed beard for the colorful robes, gaudy necklaces, tassled hat and that strange beard bracelet thing.
3. The climactic CGI scenes are all pretty much cookie-cutter action scenes, in many cases either completely irrelevant to the plot (such as it is) or only bearing a loose tangential relationship to anything important to the story.