Freaking loved the movie. I feel it was the best TMNT film since the first one. And am I the only one who liked how Shredder WASN'T the focus of the entire thing?
BTW, in case anyone wants to know, Karai is Shredder's adopted daughter. She appeared in the 13 issue mega blockbuster TMNT miniseries, City at War. She takes on the role of the Shredder after the Turtles killed him all the way back in the late 80's (I think... I have the comic, but I can't remember when it was published).
Anyway, it played a lot like the new series but with deeper writing. I will reinstate that Shredder's absense makes the film stronger, as... well... we wouldn't want to see every Batman movie with the Joker in it. That would lack variety.
I can't recall the second film that well, cuz I haven't seen it in years, and New Line was SUPPOSED to release special edition DVDs of the 3 original films, so I won't go out and buy TMNT2 just yet. But I think Shredder's part was pretty much cartoonish, and Vanilla Ice sucks... as in he sucks all the fun out of the movie.
Of course, I don't think they ever could have done their true origin in a live action film... cuz it involves Utroms and space travel to a world ruled by Triceritons... They did hint at the Utroms in the original script for 2, but they changed it at the last minute (too bad... Jim Henson productions almost made an animatronic Utrom....)
Utroms: Odd brain like aliens who have android bodies. They are peaceful scientists. One group accidentally managed to get stranded on Earth. The teleporter they created to get back home made the same chemical waste that mutated the Turtles.