The Flash movie seems to be an exciting movie with the trailer, and here how I would rate it based on several factors.
Visuals[]
The visuals seem awesome, very cool. Flash entering the Speed Force seems awesome. Also, the Batcave, looks awesome, along with Michael Keaton, who still looks awesome 31 years later as Batman. Though on a side note, the collapsing buildings when they revisit the events of Man of Steel didn't really look cool. Final conclusion: 9/10
Story[]
Though I would've done something else, the story seems pretty cool with Flash ruining the timeline, ending up in Earth-89, and meeting Michael Keaton's Batman. I LOVE how there side-stepping the events of Batman Forever and Batman and Robin. Though I have to say I'm disappointed with Zod being the main villain instead of the Reverse Flash or the Dark Flash being the main villain. I am also disappointed they will not be making any other DCEU movies and that Michael Keaton will not be staying. I am very disappointed with James Gunn's DCU. Final Conclusion: 7/10.
Casting[]
Let's get right into it, I'm pretty impressed with Sasha Calle's performance as Supergirl seems actually pretty good. Ezra Miller's performance is actually good, as I like his performance in the Snyder Cut. I saved best for last, Michael Keaton, this is going to be awesome, he is still my favorite Batman actor, more than Christian Bale, Ben Affleck, Adam West, and Robert Pattinson (seriously, The Batman is overrated). Final conclusion 10/10.
FINAL CONCLUSION[]
After doing some calculations, it's 8/10 or a B, so, pretty good movie I'd say.