Like many sequels, this one obviously didn't live up to the first movie.
It was much more comical and the animation quality wasn't as good (though it was still pretty good in-and-of itself, especially considering it's a sequel).
What I like about this movie is that, first of all, it's a prequel--it goes back to when Copper and Tod were kids and shows them already arguing with one another, as Copper has decided to hang out with a group known as the Singing Strays instead of his best friend.
This movie is extremely cute and the Singing Stray characters that are introduced are charming; I have no complaints about their design and, actually, their singing isn't half bad. The songs are kind of corny, but they're catchy and they're sung well (Reba McEntire plays the voice of Dixie!). So, though the soundtrack isn't the greatest out there, it's nice to listen to if you're in a good enough mood to do so.
Again, the animation isn't the greatest. The first movie obviously focused a lot more time and energy on more realistic and detailed movement of their characters. But, since most sequel films are produced on low budgets, this one wasn't bad. The animation was smooth and the use of CGI wasn't too horrible (except maybe the ferris wheel, but that didn't last long, so it can be forgiven).
I liked how much Copper, and the other original characters actually looked like their first movie counterparts (unlike how much Simba didn't look quite like Simba in the second Lion King movie--though the animators tried). The only character that I didn't like the apperance of was Tod; he just wasn't as cute as he was in the first movie, I guess because they tried to simplify his in this movie...
Also, it's a small issue, but his movie has an over-use of color. Colors are great and all, but this movie is literally BURSTING with them--things are just a bit too bright throughout the entire movie--I mostly bring this up about the backgrounds (where as the first movie used lots of colors, but they were closer to natural tones; and that's regardless of whether or not the settings were in the woods or at a carnival).
Above all, it is what it was meant to be--an entertaining sequel/prequel to Disney's original movie that serves little purpose but to make you smile for a little bit (which is does). It's worth a watch if you're a Disney/animation fan, or if you just liked watching animated films in general, but don't expect to be emotionally tugged.