This is a beautiful movie, I don't know why some people don't like it, but I've been a DC comics fan for more than a decade and if you read this you can trust my words, you must watch this movie.
This has the vibe of Golden Age as a Justice Society story should have. The animation is amazing too, actually way better than any N52 animated movies, and the most important things that are done well in this movie are the emotions and the pacing, at any point you will not feel that anything is rushed.
At the end, its just a new and better start than before, and you should support the creators by watching their movie and encouraging them to do even better in the future. After all, the Justice League hasn't even been formed yet and this is 2nd movie of this new DCAU. I sense greatness out of this start👍.