However, Teenage Mutant Ninja Turtles II did have a few things against it going in when it was released in 1991. Most notably, Paige Turco replaced Judith Hoag as April O' Neil and the film left out Casey Jones entirely (Elias Koteas), only to bring him back for the third installment. The darker tone of the first, which leaned more towards the comics than the cartoons, also seemed to be sidelined in favor of a more slapstick approach to the characters. And how did Vanilla Ice get into this?
After seemingly defeating their nemesis, the Turtles begin to mop up what's left of the Foot, while taking it easy. However, a news report by April on TGRI brings their past to light, as a canister containing 'ooze' from TGRI is what mutated them. This does not escape the notice of a very much alive Shredder, who wants the ooze to create his own mutants in order to get his revenge. Determined to uncover the secrets of their past, the turtles head to TGRI, only to confront – and lose the last canister of ooze to – the Foot. Now, with Shredder in possession of the ooze, the final battle will be mutant versus mutant.
While there is some inherent suspension of disbelief required when watching any of the TMNT movies, Secret of the Ooze really pushes it. If TGRI knew or even didn't know what the ooze was capable of, why did they have hundreds of canisters and why did they keep them for fifteen years, only to suddenly dispose of them? If the original ooze was a mistake, why and how did they replicate it? How did Shredder, after using the ooze to create Tokka and Rahzar, end up with a full canister? Aside from these questions, TMNT II also scraps several things that made the first work much better. There is no romance nor is there any infighting between the turtles, which gave the first some heart when Leo and Raph patched things up. Also gone is the "art of invisibility" – in one painful scene, the Turtles dance with Vanilla Ice on stage at a club. The final battle, between the Super Shredder and the Turtles is also quite lame, with no blows exchanged. Tokka and Rahzar also give the film a really cheesy feel, which certainly doesn't help it relate to a wider audience. However, the main audience was and will always be kids, who are certain to enjoy the film for what it is.