Edit: the worst part, you can visibly tell when both versions of Barry are on screen which one was real and which one was a CG double.. not a clone shot, a CG double, that doesn't look good.
...
To start, the visuals meant to portray time travel are wildly confusing, although artistic, super distracting.
For the most part you can tell at a glance what is or isn't CG, most of the characters and cars where quite obvious.
Story wise it was inconsistent with the comics and also very slow. Overall not interesting, especially for a flash point movie.
Dialogue between characters was garbage unless it was Barry 1 talking to Barry 2.
The best part was the fight between Kara and Zod, but mostly the end minute Cameo.
10/10 don't waste money seeing this in theaters. Wait until a friend rents it so you can watch it and hate it for free.