While faithful to the original, frustrating, outdated gameplay occasionally bogs down an otherwise fun, nostalgic ride.
The question isn't so much in the quality of the port, but with the aged gameplay itself.
Turtles was designed as a quarter eater, and that hasn't changed. The button-mashing control scheme works well, but you'll often find yourself frustrated by dying due to hordes of dumbed-down enemies and boss fights designed to drain your energy. As the game progresses, enemies don't get harder or smarter -- they're just more of them, and they team up on you in a rather "cheap" manner. It feels that certain stretches are not about skill, but just about mashing your attack buttons, knowing that you're taking damage, in hopes that you'll outlast the latest wave of attacks.
This results in the player having to learn tricks to outsmart the repetitive AI in both boss-fights and traditional game environments. This, however, is not a fault of TMNT, specifically, but that of an entire generation of gaming.
The control scheme is simple, with only two buttons, used together or separately to form attacks. It would've been nice to have the option to map moves to additional buttons, but no feature exists.
As far as graphics and sound, they're just as you remember them, and while it would've been nice to have an updated look and soundtrack, it holds up pretty well, considering the game is nearly 20 years old. The cartoony style is pretty forgiving.
There is an offline game mode, where you have unlimited lives, but the real meat of the game comes in its online multiplayer. Over XBOX Live, you can team up with up to 3 others to take on Shredder, and with a limit of 20 lives per character, presents a nice, yet fair, challenge, and the achievements are varied and interesting enough to keep you playing. Unfortunately, the characters aren't balanced, and everyone still wants to be Donatello.
If you enjoyed the game when it was first released, and plan of playing online, it's definitely worth giving it a try again, especially for the low price of $5.