So I finally got around to watching this on 4Kids's website. Overall, I liked it, especially the scene where the Turtles meet their Mirage counterparts. The whole look to that scene was very cool, with its B&W comic book style and of course, the grittier, growly portrayals of the original Turtles. There was good tension when the device that is supposed to save the world from being engulfed doesn't work right away, too. In fact, the whole end to the episode reminded me of the Duckman episode "Color of Naught", wherein everything is reduced to sketches and eventually nothing.
TMNT 2003 in TMNT 1987 world was amusing, too, especially since they basically state they rescue April every day. The banana peeling scene, as I had seen it earlier in a gif in this thread, had me smiling wide.
Biggest laugh in the movie was probably near the end, when Krang does his trademark high-pitched growl and then says, "Excuse me", like it was a belch.
I did like how the film didn't overstay its welcome, either; 78 minutes was the perfect length for this.
My only real complaints?
-They couldn't use the familiar 1987 Turtles melodies. I assume this was because they couldn't get the rights to them, and the melodies they DID use were OK and sort of evoked the feel of the old show, but I would've loved to hear those original songs in this movie mixed in with the 2003 melodies. Heck, they could've done another self-referential joke: One of the 2003 Turtles could've said: "Jeez, how many times does this music cue play?!"
-The VAs for the 1987 Turtles were a very mixed bag. Rebecca Soler as April was DEAD ON (seriously, I looked on imdb to see if it was the original VA, that's how close it was), and Bebop and Rocksteady were generally good, but the Turtles themselves fluctuated all over the place. At times, they sounded somewhat similar, but then other times, they barely sounded like the originals. The best was Raph; the worst was easily Leonardo, who didn't sound like Cam Clarke's portrayal at all, except in brief moments.