You'll find a lot of people who consider the original "Teenage Mutant Ninja Turtles" to be a classic. I'm one of them. However, I'm in the minority of people who considers the sequel to be a classic as well, just on an entirely different level. Though it doesn't follow the comic book, lightening the mood and upping the humor level gives the film the tone of the cartoon that more people are familiar with.
The Shredder, surviving the fall into the garbage truck at the end of the first film, kidnaps Professor Jordan Perry, head of TGRI, the company responsible for mutating the turtles. Creating two monstrosities of his own named Tokka and Rahzar with the scientists help, Shredder takes the advantage and even has the final canister of ooze that could mutate the heroes back into normal amphibians. With the deck stacked against them, the Turtles head into action with their new partner Keno (Ernie Reyes Jr.) to stop the Foot Clan from a complete take over of New York.
Right from the start, this sequel establishes a new tone. Light, which was notably absent from the first edition of this series, is used here and the fighting style relies more on comedy than real martial arts. Fans of the first film were surely stunned by the mood change, but kids who were disturbed by the rather tragic beating of Raphael in the first film have no worries here. Of course, this film is probably best known for the rather blatant appearance by Vanilla Ice, suddenly coming up with lyrics on the spot about the Turtles who have busted into his concert even though he knows nothing about them.
Directed by Michael Pressman (Boston Public amongst other TV shows), there are a few obvious, though minor, problems in the continuity. Blatantly obvious is Paige Turco replacing Judith Hoag as April O' Neal. She's gentler and softer, likely a change for the better. Most of the Turtles crew has new voice actors (Cory Feldman fails to return as Donatello) and the canister of ooze doesn't match the one shown during a flashback sequence, but that's a nit-pick.
Animatronics, supplied again (and also for the final time) by the Jim Henson Creature Shop, are a major improvement. Lip-synching is flawless and the suits never bend in odd places like they did a few times in "TMNT." The designs for the new mutants are fabulous, looking perfectly evil and downright stupid at the same time. The final battle includes Super Shredder, played by pro-wrestler Kevin Nash (noted as Kevin "Clash" in the credits). Oddly, the shelled heroes never even lay a hand on this superb suit making for a very anti-climatic ending, but it's a minor issue.