TMNT was one of a few games from the period that featured copy-protection via a code sheet printed on so-called "copy proof" paper. This is dark maroon paper with black ink which most black and white copiers would not be able to copy in a readable form. The code sheet which was stapled into the game manual, featured hundreds of four digit numbers in a grid which you needed to look up to get into the game.
Buggy DOS version
The DOS version of the game released in the USA is infamous on its own right. Apart from being usually derided as a poor game (nothing unusual when it comes to games covering comic book, film or TV licenses), a glitch made it impossible to reach the end of an intermediate stage. The only way to reach the further stages was by using passwords. Apparently the UK version of the game (labeled as "Teenage Mutant Hero Turtles", as opposed to "Ninja Turtles") corrected this bug and can be finished without cheating.
The reason why the Turtles all wear red masks on the cover is because that's how it was in the comics.
In the movie The Wizard
, Jimmy is seen playing the Teenage Mutant Ninja Turtles
at the arcade at the Casino in Reno.
The translated Japanese title is "Ultra Turtle Ninja Legend".