Flo Lieb’s review published on Letterboxd :
This felt like a comic book movie and I kind of appreciated that.
Which doesn't necessarily make it a success. The first act is especially clunky with its relentless armada of exposition. Clearly Justice League doesn't bother that much with continuity (going Fox' X-Men route rather than the pedantic Marvel connectivity).
Cyborg is essentially simply dropped in the story with hardly any backstory or explanation given to his getup. If you're not familiar with his origin you might've had trouble comprehending his character. The same goes for Flash and Aquaman, both of which are presented with some exposition to their pending solo outings. But just as Cyborg not giving any real context which makes Mera more a cameo for fans than provide an idea of Atlantis and Arthur Curry's place in it. Wonder Woman now is closer to her comic book powers, moving faster than the eye, jumping in the sky - I don't mind it (rather welcome it, actually) but this is a more powerful Diana Prince than we saw this year in Wonder Woman.
Jumping from one plot point to the next with every character spouting out expositional lines (Barry and his dad about the murder investigation of his mother, Mera and Arthur about his role in Atlantis, Martha and Louis about a world without Clark) makes the first act very unsettling. The story gets no time to breathe and unfold, everything happens overtly fast. Luckily the plot slows down in the middle of the movie after the group's first encounter with CGI baddie Steppenwolf.
Steppenwolf himself is neither a worse nor a better villain than any of these superhero movies. They're all designated world destroyers without knowing their own agenda themselves. Sure, Cate Blanchett was actually a real person walking around as Hela in Thor: Ragnarok instead of a pixel creature from the abyss of VFX but when it comes to motivation she ain't that far from Steppenwolf. He did seem at times ridiculously powerful (his takedown of the Amazons in the movie's best action scene) and yet got his ass handed to him in the climatic battle once Superman showed up.
I won't fault the sometimes uneven CGI (Themiscyra looks worse than in Wonder Woman) since I don't expect a story about superhumans fighting flying space zombie beetles to look photo-realistic. The threat probably was warranted to get the band together, the action was so-so as was the group dynamic. Don't know if it was Snyder oder Whedon whom to thank for all those attempted one-liners but they didn't really land (Aquaman's "My man!" battles it out with Cyborg's "Booyah!" as worst line of the film). That being said, I totally cracked up about Flash's "Dostoyevsky" bit.
Ultimately this movie lacks the interesting approach of BvS: Dawn of Justice but jibes better than the former. It looks and feels like one of the DC Animated Justice League movies - only as live-action. And I kind of dig that - at least I had a better time than during the three Avengers movies (Civil War included).