I gave this film a C+ yesterday, but upon rethinking it, this probably deserves a D or perhaps an F.
Batman vs Superman has a few moments of fun, but these are inevitable given the source material being plundered. As Zack Snyder said, Batman and Superman are not flavours-of-the-week like Ant Man, they are part of American mythology, so I don't think we should give Snyder much credit for harvesting/strip-mining the mythology. He needs to be able to grow it (which I think he did with MoS), and really with BvS I'm relatively confident that they are harming the franchise and harming the brand.
I do notice on this forum and another that long-time fans did find some joy in the film, as I did. I think it relates to Snyder's cinematic style of the premature nerdgasm. Dawn of Justice contains elements from Both The Death of Superman arc and The Dark Knight Returns, both of which are climactic stories that worked very well because they were built on a strong foundation. They have some legendary panels and sequences of panels, such as Lois Lane taking a helicopter to find a dying Superman fighting Doomsday, and then crying over his dead corpse as the Justice League watches powerlessly, or alternatively the panel of Superman's frail body after being hit by a nuclear blast. These were really great panels in the comics because they fit in the story and made them famous. I remember them and you do too. They worked well in their stories because they were payoffs to long ****ing chains of setups. Snyder implements them without the setup, and I don't think they work for the general audience that doesn't know the mythology well. However, the passionate fans are already invested into these characters prior to seeing the movie, they've already been going through the setups for 15 years, 30 years, and so on, so for them it feels like a payoff.
That's not good though. First of all it means that these great stories now cannot be used for a long time as Snyder has used them, he has harvested and strip-mined the DC comics pantheon. Second, though the fans may have felt a payoff at some of those scenes, the general audience does not. They don't get the same emotional resonance as we do from scenes like the funeral scene, as such the movie can be regarded as a form of asset stripping. The 1938 joke for example will be completely unfunny to anybody that doesn't know that Superman started in 1938, which is ~99% of the audience. As such, it's probably not a good joke.
Finally, this movie has done virtually irreparable harm to the franchise since numerous important characters have been undermined. Jimmy Olsen is dead. Lex Luthor is a henchman of Darkseid rather than his own person, and the reason he's evil is that his father abused him. Martha and Thomas Wayne, who have always been portrayed as peaceful, are now violent badasses. The damage done to Superman is something that I don't see as fixable: Rather than addressing the Zod death to lead to the no-kill rule as promised, they double down by having Superman kill Zod again since he is reincarnated as Doomsday. Further, it's likely Superman killed that black terrorist guy at the start by kicking him through walls. Finally, Batman's vision of the future shows that Superman becomes killer if he doesn't have Lois Lane to anchor him, which is subsequently explicitly confirmed by Flash travelling back in time. This is really a bizarre evolution in characterization for Superman's no-kill rule: Previous to Snyder he normally didn't kill, then after MoS we heard he needed to kill Zod first to develop a no-kill rule, then in BvS we learn that Superman is a killer whenever he doesn't have Lois Lane. It's not just bizarre actually, it's gross.
This is a deeply profound failure of a film.
