While Superman's actions are undoubtedly heroic, Batman begins to feel that if Superman isn't made to deal with his own mortality and put in his place, he will assume himself to be a god, an authority unto himself. As the action in Metropolis unfolds and these two icons of the superhero universe battle it out, Superman's nemesis Lex Luthor creates a monster called Doomsday to destroy Metropolis. It's only Batman, Superman and Wonder Woman who have a chance at stopping Luthor and Doomsday.
It's important to know that while all the usual elements of a superhero flick are in place, this is a somewhat different kind of superhero film. It's also pretty dark (given that the Dark Knight series and Man of Steel were intense enough by themselves), and gradually builds up to a climactic conclusion.
Bruce Wayne (Affleck) might have a somewhat inexplicable grudge against Clark Kent (Cavill), and in his anger, he has to be reminded by Alfred (Irons, superb) that taking on Superman would be suicide. After all, how does one defeat a man who cannot be harmed by anything - except kryptonite, of course. So Wayne dons his cowl, a considerably up-armored suit and levels the playing field a bit, with the help of an array of special gadgets and materials.
Those aware about comic lore would know that these two have faced each other off before. But on the big screen, the fight sequences are furious. It's also about a clash of their ideologies. It's pretty heavy and this will put some off. However, Jesse Eisenberg's Luthor is terrific - from his look, to his mannerisms; a psychotic, conniving villain straight out of hell, who quotes Nabokov. Gal Gadot, as smokin' hot Wonder Woman is absolutely kickass. Affleck is good, but you'll definitely miss Bale's Batman.
Characters are briefly introduced and there are certain scenes that might look random (Batman's nightmares, for example) but all reference the DC Universe. The movie is packed with references - both visual and dialogue-wise - to classic comic lore. Underpinning everything is Hans Zimmer and Junkie XL's score. An artillery barrage of action.