I saw it today and it was really fun to watch! I walked out of that theater feeling like it was 1993 all over again!
It's really not that bad for an animated comic book film. If it had been released straight to DVD, I would've been really disappointed, because seeing it in theaters reminded me so much of when I saw the third live-action film in theaters when I was seven.
The story seemed fine to me, very much like something straight from the comic book itself. I agree that Shredder should've been involved, but Karai (the female Foot Clan leader you saw in the film) did hint that he might return. So let's hope they make a sequel, and we can see a CGI Shredder. But I love the whole monsters from another dimension plot and everything else that surrounded that.
I want that soundtrack to the film. All of the songs played in the background during the action sequences was off the chain, including that one called "Shell Shock" that was played during the end credits.
I agree that the CGI animation fit perfectly for this film (with all due respect to Jim Henson, puppet suits and animatronic helmets get old after a while), mostly because half of the speedy moves performed by the characters would've been physically impossible for live actors. Every time I ask someone what was their favorite scene in the film, it was the fight sequence between Leo and Raph, which I have to agree on. The CGI really proved its worth during that scene, with the rain and the awesome kicks and punches by the two Ninja Turtles.
Like Speed Tracer said, Casey Jones is still the man, and Chris Evans (Johnny Storm from
Fantastic Four) made me appreciate the character more than I already had, just as he did for The Human Torch. The man is just so darn good at bringing these characters to life. Sarah Michelle Gellar even did a good job as April, who I don't really mind for not being a news reporter in the film (because if anyone has read the comics, you'll see in later issues that she became a ninja just like the TMNT and even had her own comic based off that storyline).
They really captured the essence of the TMNT and Splinter well in this film. I will really miss Mako after seeing the movie, because he really made me believe he was Splinter from his performance. But whoever voiced him in the scenes that were recorded after his death sounds like a great replacement (I thought it was Mako in every scene), and I can't wait to hear him in the new season of "Avatar: The Last Airbender". And the voices of the Turtles were wonderful as well. James Arnold Taylor (the voice of Leonardo) is becoming my new favorite voice actor.
I seriously want to see this again. But, for now, I'm going to settle on playing the video game to recapture all of the great moments in the film.