Yeah, while the Turtles have been a pop phenomenon, that did not protect them from being in bad films. This one is a promotional video meant to advertise the (at-the-time) upcoming L.A. Metro's Blue Line, which is still in operation (although as of this review, some parts are closed for repairs).
In this video,it begins with an intro where the narrator talks about Los Angeles, and how it is plagued by clogged freeways and exhaust vehicle polluting the air. That's when it hits you. This isn't just a promotional video, it's also an educational video.
April O'Neal is in L.A. to report on it, but is reporting that the information is not being received by the people. This is the work of Gridlock, a human villain who only appear in this special, and is using a weapon known as the Gloomsday device (which looks like Gridlock raided the armory of the Ghostbusters and stole Egon's Giga Meter and made some modifications). However, the Turtles are in town as well (possibly because they can't leave April alone over fear of her being captured again) and when April calls them about the situation, the four decides to help her spread the word and try to stop Gridlock.
TBH, this is so-so. The Turtles are portrayed as costumed actors wearing costumes designed after the Turtles' action figures. However, this movie does get the VAs from the cartoon (which was still airing at the time) to do voice work for this. Also, there are some jokes that are hit-or-miss (one scene had the Turtles oogling over a picture of a pizza like it was a Playboy pin-up, and Michelangelo makes a Star Trek quote when they are at the RTD control center). Also, Donatello and Michelangelo get their neck colors mixed up, which can irk hardcore TMNT fan who love to complain about animation errors, but the video cover is hilarious for all the wrong reasons (as it shows Raphael using a bus to run down Leonardo and Donatello in an act of road rage, making me wonder if the two stole his pizza or something?). It's a so-so movie that is dated due to it being made when the Blue Line is close to opening, but is worth watching for a laugh or two.
