Review does contain spoilers -
Upon sitting down within the theater, I had specific expectations. Although that was my first mistake.
The movie starts out good. You see his powers at play and Batman in action. The latter I was more interested in. Shame Ben Affleck won’t be reprising his role as Batman again. I do wish he had his own standalone movie. But after the first climax, that’s when the plot begins to slow down.
I am no fan of Ezra as a person, but I could ignore that during the movie. What I do dislike however is how he acts as Barry. Particularly when he is preparing to run and how he runs. His starting position just speaks cringe to me, and the way he flings his arms so widely doesn’t work either. I have been told by others it’s a technique that ice skaters use during races. But that’s the problem here. One, he’s not on ice and two if you’re going so fast with the speed force, I highly doubt swinging your arms like so is going to make any beneficial difference. Including the amount of needless poses and movements that he does.
Skipping ahead to when Iris is in Barry’s room, the two talking amongst themselves. Barry’s thoughts are spoken out loud, including he uses his computer in front of Iris. Revealing so much in so little time as for his plan to alter time. Of course it wouldn't have mattered since he was going to change the timeline regardless. But he had little to no self control over his identity as the Flash. To the point it didn’t feel like it was Barry at all.
Upon leaving, Barry runs faster in a single direction, using the speed force to manipulate time. The way at which the timeline was shown at first was honestly very interesting. But as it appeared throughout the film, it only felt more and more unclear. Including the multiverse aspect of it.
For something called the “timeline” nothing about it was linear. I was expecting a long path for him to run down, as everything around him changed as the clock ticks backwards drastically. Not a sinking sandpit with him at the center. Every movie does time differently. Other than many plot holes throughout the film, time was done unlike any film before it. Like the whole premise of it meant nothing to the writers.
There being a second Barry was a mess too. Having to deal with only one Ezra was a task. Two of them was another problem entirely. Doubling down on Barry’s awkwardness that Ezra conveys far too much. Including this other Barry became a semi antagonist, but fell short on being compelling. Not even Reverse Flash made an appearance, which honestly was very disappointing. Meaning the film lacked a main villain against Barry.
Several action sequences were either too short or anticlimactic. Supergirl vs Zod is an example. I expected a huge brawl, the same level as in Man of Steel. But that unfortunately did not happen. Including the kryptonian soldiers felt like they were bathed in sunlight already. Easily reacting to Flash’s speed when it shouldn’t be possible.
Michael Keaton as Batman and the number of cameos was the good aspect for me. Especially Nicolas Cage as Superman in another universe. But that alone wasn’t enough to save it. As another person wrote, not even Keaton could bring this film out of the gutter.