It's hard for me to put it into words, but basically everything is wrong in this clip, everything: https://www.youtube.com/watch?v=Z6oUJoJ3NDg
I don't even know were to begin: https://www.youtube.com/watch?v=MgZPw_k44n4
None of them can act. None.
The acting wasn't really the problem - Gal and Batman had some cringeworthy lines and delivery, but beyond that, it was pretty standard. I actually very much like the cast overall, and think Cavill as Superman is spot on,.
It's the plot/story/villain, direction and even the musical score, that's the huge failure.
While I liked Superman was badass (the stink eye to The Flash was epic), he was too badass, and others were a joke in comparison. Story was rushed af. It had potential, I'll give it that, but it should have been another year before coming out, with a better sensical story.