I will admit the first part before the comic takes place is a little stale...at first...then it gets deeper into foreshadowing the tragic events of the legendary comic.
I'd recommend skipping the first 30 minutes if your kinda a purest of the original comic.
The animation is top notch, they got the Best Actors for these characters, Mark Hamill as the Joker, Kevin Conroy as the Batman, both playing their roles amazingly as per usual, they always go the extra mile, and for one of the greatest comic books in history, this is no exception.
even if you aren't a fan of the fresh new story before the comic takes place, this is a must see movie.