*SPOILER ALERT* I may divulge certain spoilers from the movie, however I'll do my best not to completely ruin it.
First, let me say that this movie was badass! While DC may be chasing Marvel as far as movie supremacy, it's years ahead of Marvel in animated films. The animation alone is outstanding. There are few parts where the quality of animation dips at all.
The interactions between the characters are great. Hal Jordan's arrogance exudes through the screen, Batman's intelligence actually shows up in this rendition (unlike in Nolan's Batman trilogy), and Wonder Woman is a total badass warrior chick. But even with all that, they manage to show how their power pales in comparison to Superman. I love the first meeting between Batman/Green Lantern and Superman. That scene is exactly what I hope for Batman/Superman to be like.
Darkseid is completely what you'd expect. A cold, towering obelisk of death. The only member of the justice league that he even seemed concerned with was Superman. He just saw everyone else as a fly that was in his way of dominating, yet another planet. A slightly new take on Darkseid's design, but in a good way.
The only gripe I have, I suppose, is some of the voices don't quite seem to sync up with the characters. Not that these actors were bad it's probably because I am used to the voices of Superman and Batman from the animated series from my childhood.
Bottom line, if you are a super hero movie fan, you'd be missing out BIG TIME if you don't see this. It's a great piece of cinema from beginning to end. I can only hope that the upcoming movie Batman/Superman follows in the footsteps of this animated movie. Let me know if you guys want me to go into a greater detailed review on the characters in the movie, thanks for reading!