I'm going to be as forward as possible without giving spoilers
This movie on the surface seems like just another shot in the dark from the people at DC, in theory it could have been great but they wrote it poorly. Instead of making a proper DC movie, it's yet another very fan-servicey marvel emulating production. If anyone is honest with themselves, the DC universe is in shambles and has been for a very long time. Instead of rebooting the universe and starting over, they're trying to hinge the entire survival of the universe on this one movie, The Flash. However on paper this doesn't work, I'm sure if you go on YouTube you can find many videos explaining how and why, this review would be 3 times the size if I explained it. That being said, it is a good idea for a movie, and if you have no care about the comics or other movies, as a standalone it is not bad.