After wallowing for years as a cartoon, there was an attempt made to bring the turtles to the big-screen again - and for the first time, as an animated film.
Why It "Ruined" TMNT: April O'Neil and Casey Jones are - for some reason - digging up Aztec relics. Naturally, this leads to a bunch of evil monsters being released from another dimension - real boring, uninteresting, and mostly incoherent enemies, all while teasing the idea that eventually you might see Shredder in a sequel mayyybe. It was a pretty boring, nonsensical plot, even for kids who were into TMNT.
To be fair, there is a pretty sweet fight between Leonardo and Raphael halfway through.
The movie that ended the live action TMNT movie franchise back in the day sent the turtles back in time to feudal Japan. From the videogames at least, TMNT traveling through time has a pretty good reputation - so how bad could it have been?
Why It "Ruined" TMNT: Pretty much everything got a downgrade in this movie - the producers cheaped out and used another effects company instead of Jim Henson to design the turtle suits (which ended up looking even cheaper, creepier, and gave them all a bunch of weird spots), the turtles literally give a Wayne's World-style "Schwing!" when seeing April's legs (for those of you unaware, "Schwing!" means 'boner', making it a VERY CREEPY THING FOR THE TURTLES TO SAY), and the film as a whole is a lot more cringeworthy than the previous entries.
And this cannot be said enough: "SCHWING!" is something the turtles say in this film.
The movie was meant to lighten up the unusually dark predecessor with more humor, a bit more slapstick, and SIGNIFICANTLY more Vanilla Ice raps.
Why It "Ruined" TMNT: I mean, there's an elongated section where Vanilla Ice performs an impromptu rap about turtles who are also ninjas. Imagine if Justin Bieber showed up in the new film and sang an upbeat pop ballad called "Girl, You Know These Ninja Turtles Represent My Love For You." Well, that would be BETTER than Vanilla Ice, because Vanilla Ice was an enormous hack who stole a Queen/David Bowie song and called it his own.
If you're the kind of person who would be upset at the idea of Justin Bieber singing a song during the climax of the new TMNT movie, you should be VERY upset at Secret of the Ooze.
The original live action film was actually a lot more ambitious than you might realize - first off, it was an independent film (and the highest-grossing one of its time) and the live-action turtle suits were the most complex thing Jim Henson Studios had ever done (in the words of Jim Henson, at least).
Why It "Ruined" TMNT: You think the CGI turtles from the Michael Bay film are creepy-looking? CHECK THIS SHIT OUT:
But beyond that general level of creepiness and the big, wide dead-eyes of the turtles, the movie had a weird darkness to it - Splinter was being tortured for a good portion of the film, April's surrogate son has joined up with a murderous gang, and the turtles straight up try to murder Shredder by crushing him in a trash compactor (not that he wasn't asking for it, but it was a pretty huge departure from the animated series, where the turtles only ever killed robots).
'This is it - the big one, the one that truly introduced the Ninja Turtles to the masses and became the foundation of pretty much everything to follow. Find a 25-35 year old on the internet, and they'll probably have a nostalgia-gasm at the mere MENTION of the animated series, the toys, or the cards (that included a pink shard of glass referred to as "gum").
Why It "Ruined" TMNT: It was a ploy to sell toys. That's all it was. It was an elaborate, decade-long commercial to sucker kids into getting their parents to buy them all the toys and merchandise they could afford. You think the Michael Bay movie is a cynical cash-grab? This show was designed from the beginning to make TMNT palatable to kids in order to manipulate them. That's right - your entire childhood is a lie.
You see - before the animated series, TMNT was a niche comic book that was meant to parody and satirize other grimdark comics of the early 80s (Frank Miller's Ronin, Daredevil, and New Mutants mostly). The entire idea was how silly it would look for giant turtles (who you'd think would be super slow) turn into quick-attacking ninjas, defending the streets of New York City.
But the general idea (moreso than the comic itself) was really REALLY appealing to merchandisers - kids love animals, and ninjas! But the comic wasn't very kid-friendly - so why not make a Saturday morning cartoon out of it that makes all the turtles goofy and fun-lovin' and softens all of the hard edges? That's just what they did. And it worked - kids bought into it wholesale.
It was a live musical tour, sponsored by Pizza Hut, and it looked like this. LOOK AT THESE GLORIOUS PICTURES AND TELL ME MICHAEL BAY IS THE ONE WHO'S RUINING YOUR CHILDHOOD:
How It "Ruined" TMNT: Not convinced yet?
Kids today will probably love the Bay version of TMNT. Which is fine! Each version of TMNT has been designed to appeal to kids of that generation. That's why you feel so much nostalgia for whatever version you grew up with. And that's why newer entries are less appealing to you.
Although, seriously, if there isn't a super-weird pizza order from Michelangelo, I'm gonna flip out.