Accept it or not this was a gem created by the Snyder. Every scene in this movie teases you about the future of DCEU. It is a tightly packed movie with almost every conversation between characters helps in the character development and teasing us about the future.
After some years this movie will definitely set a bench mark for Superhero movies, even though it has some minute errors regarding the plot.
Many complaining about the tone of the movie but unfortunately that is how DC is differentiated from Marvel. DC will give us ground to earth reality in the fictional world on the other hand Marvel gives us entertainment. If DC make lighter movies as of Marvel we will hate DC saying that they copied Marvel. If they made movies as of now, with serious and darker tone the haters are complaining about the tone. Believe me, no person in the world, it doesn't matter how much powerful he is, will crack jokes in the middle of war.
This is how a movie has to be, instead of just accepting the existence of super heroes, which will never happen in real world, this movie debated the whole concept of existence of super heroes mainly Superman.
As far Superman is considered he is the most physically powerful character, then the only way to make him suffer is to break him mentally and psychologically, that what Zack has done. On the other hand Batman was already broken man with the death of Robin in the hands of Joker and realized "the world makes sense only if we force it".
And major issue everyone complaining about is Martha. Batman didn't stopped killing Superman because both of their mother's have same name. The reason behind it is he figured out that even Superman , the alien, have the human mother when makes him realize that superman is also human. And sees his helpless situation during his parents murder in the Superman who is pleading to save his mother. And the name Martha just acted as a catalyst.
Some are complaining that is not Batman V Superman just Batman and Superman, actually it is ideology of Batman V ideology of Superman, not the ultimate gladiator fight. This ideological differences between "the son of krypton" and "the bat of gotham" is going to resonate and echoed in the future DCEU movies which is clearly shown "Knightmare" sequence where The Flash warned Bruce about the coming disaster with the heel turn of Superman due to the death of Lois Lane.
The music department lead by Hans Zimmer has done a fantastic job. The music defines the darkest zones of the Batman and Superman characters and the intensity in every scene especially the Wonder Woman scene.
If Warner Bros. wouldn't have involved in the way of Snyder, and let him release the 3 hour cut this movie would have easily crossed 1 billion mark and would have been a great start for the DCEU.