Early on in the production of Teenage Mutant Ninja Turtles, there were signs that the filmmakers didn't quite understand the basic appeal of the property they were attempting to revive. First, there was the rumor that the turtles were being reimagined as aliens, for some reason. This obviously would have raised some semantic issues, at the very least. While that never came to pass, one creative decree that did make it into the final product was the decision to jettison the clean, classic design of the 1980s in favor of a messy, chaotic, downright ugly interpretation of the turtles, which made them look less like their former iconic selves, and more like gritty, monstrous, live action siblings of Shrek. Possibly the greatest blight attempted on the movie was the shortening its name to simply Ninja Turtles, simplifying the original title to its most basic joke, and robbing it of so much of its pulpy, trashy glory. While this early decision may seem like an innocuous effort to maximize tweetability, to me it indicates that the filmmakers didn't trust the inherent ridiculousness of the source material, which goes a long way towards explaining how they ended up with such a bland, conflicted, mess of a movie.
While not all of the production's terrible ideas made it into the final film, the classic origin story of the turtles was very subtly mutilated in order to shoehorn it into the movie's uninspired, cockamamie plot. Now I don't object to changing the source material for an adaptation, but in this instance, every single change they made, every omission, every new connection they tried to force was built upon untenable coincidence, and led to a myriad of confusing inconsistencies. For example: April O'Neil is the first non-criminal in the movie to witness the turtles in action; later, with knowledge of their existence, she follows them to a rooftop and takes their first known photo. Later still, it's revealed that when they were still just Baby Normal Crawling Turtles, they had been April O'Neil's pets. In fact, it was her father's scientific experiments that turned them into the anthropomorphic mutants that they became. The film makes no connection between these two facts. It's just utter happenstance.
Another doozy: in every version of Ninja Turtles that exists, the titular foursome are masters of "ninjitsu," and their archenemy, the Shredder, is the ninja master of a widespread underground crime network. Originally, the turtles were taught martial arts by a trained rat that mutated along with them, and the express purpose of this training was to pit them against the Shredder, who had murdered his human owner. Granted, this is an outlandish premise, but as comic book origins go, it's completely logical. In the new movie, Splinter was a fellow test subject, meaning the scientists experimented only on four baby turtles and an old rat. Fine, whatever. Once they're in the sewers together, Splinter has a realization: the turtles are never going to fit in above ground, but their unique genetic makeup might make them useful in helping surface level society. At this exact moment, he stumbles across a book of ninjitsu diagrams. As far as we know, he has never seen a single karate chop in motion, and yet, we are to believe that he became a martial arts master, and trained four others simultaneously, all from what amounts to little more than an Ikea karate manual.
The movie helps ease any confusion this might cause by almost completely leaving out anything resembling martial arts. I counted about three instances of the turtles using what looked like actual karate moves in battle. Since they are huge, superpowered monsters, they can now rely on brute strength alone--and extended shell sledding--to best their foes. When the Shredder is finally, briefly introduced, we witness him dominate an opponent while completely bound by ropes. Could this man be a worthy foe for our newly super (non-)human heroes? Who knows? We never actually see him battle the turtles as a human being. Directly following his introduction, his tech millionaire cohort gives him a robotic metal suit, making him even more powerful than the turtles, and ensuring a final battle that is yet another fully digital smorgasbord of ugly, loud, sensory numbing violence, with all the emotional thrill of watching someone else play a video game in slow motion, and lacking in any of the grace or excitement of an actual martial arts fight, even one of the awkward costumed fights from the first TMNT film adaptation. Oh, and after that initial introduction, the Shredder is never seen without his body armor again.
There is a theory that the Shredder's lack of screen time may actually have been the result of last-minute changes to the script: you see, another leaked rumor had it that William Fichtner's character, evil tech millionaire and highly caucasian Eric Sacks, was actually going to be the Shredder all along. Like the other unsubstantiated rumors I mentioned earlier, this brought on a huge, angry outcry from fans. It's not hard to imagine how they could have excised a final reveal: the Shredder's helmet is removed to reveal the face of Sacks, who had taken up his master's mantle here in the US. A couple other minor tweaks, and the addition of Shredder's brief non-robo-suited appearance, and you have something closer to the source material. However, despite a blurry resemblance to the original property, the filmmakers never crack the code of what makes the Ninja Turtles work. Instead of chopsocky ninja action, they go with almost completely abstract CG freneticism. Instead of a Ghostbusters-like comic/sci-fi "realism," they ape the deadly serious tone of The Dark Knight (when April O'Neil first sees the turtles fighting, they are terrorizing Foot soldiers from the shadows of a bay front shipping yard... essentially the exact scene that introduced Batman in Batman Begins). In fact, the titular Ninja Turtles are practically reduced to supporting players; they don't enter the movie as characters until about half an hour in. As I said, I'm all for creative adaptations, but for all the concessions made to the fans, the filmmakers somehow didn't grasp, or just didn't care, that the heart of this franchise is the turtles themselves. I mean, come on: it's right there in the name.