Actor Allusion: Somehow managing to allude an actor who isn't even in the game, one bit of dialogue references the fact that Rob Paulsen was the '87 voice of Raph and the '12 voice of Donnie.
Donatello: I had this weird dream that you opened your mouth and my voice came out.
Raphael: You creep me out sometimes.
Keep Circulating the Tapes: The game has been delisted from every digital distribution store it's ever been on. The fact that the game was never given a physical release only makes this worse, since it basically confines the game to those who had purchased it back when it was available and those who can find a used console with the game in it (the latter method being a crapshoot at best).
Box Office Bomb: Budget, $135 million (not counting marketing costs). Box office, $82,051,601 (domestic), $245,623,848 (worldwide). Things could have gone very badly if the movie didn't do so well overseas and in DVD sales. The consequences? Viacom's quarterly profit reports went down and the planned third film was scrapped.
Celebrity Voice Actor: In the Mexican Spanish dub, Rocksteady and Bebop are voiced by YouTube's bloggers Gabriel "Werevertumorro" Montiel and Alejandro "Alex" Montiel respectively, and Krang is voiced by comedian Facundo Gomez.
Creator Killer: The second Paramount/Nickelodeon TMNT film was one of several 2016 bombs that mixed together with a shareholder revolt at Viacom from Sumner and Shari Redstone over CEO Philippe Dauman's handling of the company; it led to Dauman's resignation from Viacom after 10 years. It was also one of the last straws for Paramount CEO Brad Grey, who resigned in February 2017 and died a few months later.
Disowned Adaptation: As with the previous movie, Peter Laird does not include the second reboot in the Q&A blog post.
Inverted with Pete Ploszek, who gets to provide motion capture and voicework for Leonardo this time rather than having dubbed over by Johnny Knoxville as in the previous film. This wasn't clear until the film actually came out, and Knoxville says he doesn't know why he wasn't asked to return.
While he's still voiced by Tony Shalhoub, Master Splinter is now motion-captured by Peter D. Badalamenti, as opposed to Danny Woodburn.
Brian Tee replaces Tohoru Masamune as the Shredder.
Tyler Perry replaces K. Todd Freeman as Baxter Stockman.
Brittany Ishibashi replaces Minae Noji as Karai.
The Other Marty: SNL veteran Fred Armisen was originally scheduled to play Krang, and was all set to shoot his scenes, but he bowed out due to scheduling conflicts. He was subsequently replaced by Brad Garrett.
Refitted for Sequel: Krang, as well as Bebop and Rocksteady were all considered for the first movie to the point of making it to the concept art phase, but didn't get in. They're finally making their big-screen debut in this one.
Role Reprisal: Mário Jorge, Garcia Júnior and Márcio Simões reprise their characters from the original series (Krang, Bebop and Rocksteady) in the Brazilian Portuguese dub. It helps that the movie's ADR director/translator, Manolo Rey, was the original voice of Leonardo.