Just finished watching the new direct to DVD animated movie. First off, I have not read the entire original story so my review will be through the eyes of a newbie not on whether its a good adaptation of the comics.
I liked this movie a lot. The animation is perfect and just highlights how much Darwyn Cooke's art style supports the translation. I wish the introduction to the characters and situations was a little more clearly defined. I have already seen one post on another site that in essence said "this is not the Justice League". I know from my knowledge of the original comics that this is in fact not the traditional Justice League but a melding of real world events in the 50's/60's to the Justice League history. A more straightforward narrative approach ala "Incredibles" may have helped to delineate the status quo of this world for an audience whose only exposure may be Superfriends. The breakout character is definitely the Martian Manhunter. I don't think I have ever enjoyed this character more since his JL international days. Enigmatic, noble, and childlike all describe his qualities during this movie with the standout scene being his absorbing of human culture through TV watching. Batman, Superman, and Wonder Woman are all good but a little more explanation on the tension at the beginning would make the inevitable team-up at the end have a little more poignancy. I thought Flash was played a little young compared to the others even though there was nothing to suggest he has less experience or ability than the others. And I wish Green Lantern would have shown up earlier in the story, Hal Jordan and the pacifism trait seemed unbelievable especially if he was a combat pilot. If it was written that he was only a test pilot BECAUSE he refused to engage in combat, then I think it could have worked better. The so-called villain gives them the common enemy the story needs to bring about the growth and formation of a true Justice League and the publics acceptance as such. And the JFK speech as the movie closes is very uplifting.
So if you are looking for a more adult (there is some PG-13 stuff in here)animated movie with good dialog, great character moments and quality animation then you can watch with confidence.