I've been meaning to sit down with the original Teenage Mutant Ninja Turtles game on NES for a while, because although it gets generally panned these days, some of its sequels (particularly II, the first Game Boy game, and IV) do get regular praise. The game was pretty popular back in the day (Nintendo Power even made it its NES Game of the Year), and although I never caught "Turtle fever" I do remember watching some of the cartoons, seeing the first movie, playing the arcade game, and playing at least part of this, the NES game.
Unlike subsequent games which were classic beat 'em ups, the NES game was more of a straightforward action game. The majority of levels have you alternating between a top-down map of the city sewers and short side-scrolling action segments where you battle enemies and navigate platformer-like challenges.
I found myself disliking the game for many of the same reasons that it seems most people do: the Turtles are completely unbalanced (Donatello is everyone's favorite due to his long reach) and the platforming is very touchy: missing a jump can require you to backtrack a significant amount, leading to tedious trial and error. The enemies do have a fair amount of variety, although not a whole lot of personality, so combat ends up feeling like a chore. The locales (mostly sewers, insides of buildings, and rooftops) are also pretty mundane.
On the plus side, the infamous dam section (in level 2) wasn't as terrible as I expected. The sub-weapons are very useful (although they're pretty much what you'd expect), and in one level you get to drive around in the Turtles' van (apparently called "the Party Wagon") and run over baddies, which was fun. Overall I didn't hate the game, but by the time I'd struggled through and got to Area 4 I'd had enough of the tedium and couldn't bring myself to work my way through the rest of it.