The choice to change the backstory of rocksteady and bebop from splicing animal DNA with the ooze to forcing out their dormant animal ancestor genes was stupid and makes no sense from an evolutionary standpoint. Also Casey jones is a prison guard with an extreme passion to be a detective? What? In the 2003 series his father was killed because of a dirty cop who was working for the purple dragons and so casey hated the police. In every other series his dad is killed in a fire by the purple dragons. These events cause him to be twisted and enraged. Both backstorys are dark and help explain this twisted man. I would have loved to see his backstory on film. Why is casey jones mad in out of the shaddows and how do they explain it in the film you ask? Well, All he ever says about it is he has "anger management issues". Wow. A genetic disorder. So epic. At Casey's core he is a vigilante. Casey's original writers literally wrote him to be a joke vigilante with cheesy lines and an overly serious demeanor to the point where it was funny. Always wanting to beat up criminals and help clean up new york. In this film he is a semi vigilante. He fights bebop and rocksteady as well as some foot clan members but never any gang members or regular criminals. It just really seems like he is waiting to clean the streets of NYC till he can do it above board as a detective and that's just not casey at all. Kraag was done so well. Shredder was close to perfect but gets frozen and stored by kraag which was a bad idea because he is the most well known villain and easiest to get behind. They should have made this movie with shredder bebop and rocksteady as the villains and Casey's introduction that would have been plenty. Imagine they lock up bebop and rocksteady, The end of the movie could've been a newscast outing mutants with bebop and rocksteady in cages with the tmnt waving and joking with the news casters on tv letting everyone on tv know that they'll be there watching with a careful eye from the shaddows cut to static on tv. Cut to kraag giving an evil speech about how he is going to take over. End film. If they would have done it this way we would have had a third movie.