Better than the Michael Bay produced movie. While better than most of the other live action ones. The cast is probably better than any of the live action ones as well. The story is also much stronger than the 2014 film.
I really like this movie, and you don't 'need' to see the other movies before it to understand the plot. There's some basic exposition at the beginning to cut to the point, and it saves devoting too much of the film to the backstory. It makes the assumption that that you are familiar with the who'how/why the TMNT are but doesn't require that you have to know it. You can watch this as a stand alone movie and enjoy it with only a few references that you may not fully understand... and given that there's about a 15yr gap between the old movies and this animated one... That's perfectly understandable and it's kinda nice to see some continuity to the old movies from the early 90's.
So the scene is set by the exposition and you can get right into the action.
The story as a whole is decent enough, most of the voice acting is rather good and anything that has the voice talent of Sir Patrick Stewart is certainly a plus in my book.
The animation is decent and the look of the turtles is definitely influenced by the original cartoons and movies. The action sequences are well animated but there are still somethings that I spotted that could have been done so much better... Like any animation with vehicles in it, for an animated movie that does so well with body movements, it was really lacking when it came to other aspects... that was a shame.
The second act was a little predictable, and the climax was pretty much as expected.
But overall it's an enjoyable movie, one that I've watched several times over the last few years.
I gave it a solid 7 out of 10... It's far better than the dreadful movie out this summer (2014), and I wrote my thoughts about that one over on it's page.
Seriously... watch this one instead of the new movie.
Overall a nice movie, the animations looked nice.
But you'll probably want to watch the previous live-action movies first since there are a lot of references to them and the story continues from there.
It got me kind of confused in the beginning.