From a graphics point of view this game is very impressive. Sadly from a gameplay angle it's kind of limited and every level is basically the same thing.
This could basically be described as a side-scrolling beat-em-up, though the uncontrollable camera POV becomes very annoying. And compared with old-school games of the same genre, it doesn't hold up. Pow, biff, bam, smack! It just goes on and on for the whole game.
There are some levels that could have been cool, like the rooftop or subway stages. How cool would it have been to chuck the bad guys off the roof or onto the subway tracks? Very, but an invisible wall prevents this from happening. It's so disappointed that a lot of exploration is cut short. In the subway level trains rocket past in the tunnels on either side of you, but in the middle tunnel (where you battle loads of bad guys) there's no trains at all. Most levels are this way, there's just no REAL interaction with the environment.
The Streets of Rage games on the Genesis were better. It's the same thing. The city is overrun with thugs headed by a big boss. You beat them up and kill the boss. TMNT does not improve on this concept. Cute graphics though.
It's also kind of easy. The game is totally aimed at kids. I've seen better, I've seen worse. But I would suggest renting the game as it's long-time appeal is drastically short.