Man, what a mess. We're like 2/3rds of the way there to an actual good Justice League movie!
The first 1-2 hours of this movie are just... they don't work. Some of that is on Snyder, since it's just his worst stylistic impulses paired with a really, really week screenplay. But you can pass that blame around, because you're essentially doing a Flash movie, an Aquaman movie, and a Cyborg movie ON TOP of a Justice League movie. So your options are "jam all that shit in there and hope it works" or "just don't bother establishing anything." They try the first approach, and it mostly doesn't work, but, well, props for trying. Cyborg actually comes across fine, since he's so closely entwined with the main Motherbox storyline, but the other two REALLY needed their own movies if you wanted to make them more than props.
I also think the Superman stuff is pretty tacked on, and outside of nice gimmicks during the action sequences doesn't ever feel needed, narratively. You get Amy Adams pining for a while, then Superman is back, and he's very useful at punching things. Like frankly you need to split this into four movies to make that all work - Aquaman -> Flash -> Justice League (team up, fight Steppenwolf) -> Justice League 2 (revive Superman, fight Darkseid).
And like, the Knightmare sequence, Christ, we don't need that. There's so much we don't need. This is the opposite of "kill your darlings." It's "Oops! All Darlings!" the movie. But there's that stretch from Batman recruiting Flash up until the "ending montage with pithy monologue" that's a really, really solid superhero movie. And I liked that part, more than I expected, almost enough to cover up the first half.
