Imagine, if you can, that the first Marvel movie you ever saw was Avengers: Endgame. You kind of knew the basics of the characters; Captain America has a shield, Iron Man is rich, Hulk is angry and Thor has a hammer and shoots lightning. You understood that these characters had come together before to fight bad guys and save the world. But beyond that, you didn't really know much more. Suddenly, you'd be asking yourself "why is Thor fat and what kid did Iron Man lose?". It would be a mess of confusion because you're coming in at the end of the story.
That's what Flashpoint is. The story, one of the most important tales not only for Flash, but for all of the DC Universe, follows Barry Allen as he travels back in time to stop the murder of his mother, only to end up messing with time and creating a world of nightmares where Wonder Woman leads the Amazons in a war against Aquaman and the Atlantians, Bruce Wayne was killed and his father Thomas became Batman and where instead of being the greatest hero the universe would ever know, Superman is held in a secret lab under Metropolis. To be blunt, Flash really messed everything up.
Flashpoint is built on decades of continuity and the understanding of who these characters are. It plays off the knowledge of the readers to give fans a cautionary tale about trying to fix things that aren't really broken and the problems that come with hubris. And sure, you can make sense of and enjoy Flashpoint if you haven't been reading Flash or any other DC book before then, but you'll have a lot of questions that the story doesn't answer. And now, that story is being made into a movie where, if things go the way Warner Bros. wants, millions of people will go see the movie and end up with the same questions.
There could not be a worse choice for the first movie to star Flash. The power of Flashpoint comes from knowing what the DC Universe was before it happened, but Warner Bros. can't seem to figure out what their DC movie universe is, so they're not really in a position to show fans a screwed up version of it. So, let's look at some of the things the movie needs to do to pull off Flashpoint.
First, it needs to really introduce audiences to Flash. For Barry Allen's solo movie to work, you need to do what Aquaman did -- reintroduce the character. Fans don't need a movie that just retells Flash's origin, but it needs to show us what his life is like. That means setting up the world of Central City, bringing in his supporting cast -- Iris, Captain Singh, Patty Spivot and the other people Barry works with or interacts with on a regular basis. Then you need to set up the big bad, which in the case of Flashpoint is Reverse-Flash. A villain from the future, Eobard Thawne gave himself super speed to be like his idol Flash. But after meeting his hero and being politely but soundly rejected by him, Thawne becomes Reverse-Flash and goes back in time to kill the Flash's mother in revenge.
Now, put all that in the movie, and smash it into the first act, because act two has to start with Flash saving his mom and altering the course of history. From there, you have the rest of Flashpoint to play out, but without Superman, Wonder Woman or Aquaman. Maybe Thomas Wayne makes an appearance to help sell tickets. The Flashpoint comic uses Flash as a way for the reader to see this new reality, but he is not the focus for a lot of the story.
Flashpoint is also a bad representation of a Flash story. That isn't to say that Geoff Johns and Andy Kubert didn't tell a great tale, but the Flash is a character who works best in the light, not the dark, and Flashpoint is a very dark story. This is a character who, in the comics, takes time to paint people's fences and carry the groceries for old Miss Maguire over on Broome Street. Flash is one of the most grounded of the DC heroes, and that is what makes him stand out. Having his first movie ignore those aspects of him is wrong. There are 80 years of Flash stories to choose from, so maybe Warner Bros. is better off looking to the past for Barry Allen's first solo story.