Not great in any respect, and good in few respects, this movie may not have the breathtaking vision found in a Pixar flick, but at least it isn't as annoying as a DreamWorks production. If you're a hardcore "film buff" try numbing your brain, if that doesn't work, skip to the squirrel scenes. I think most others will be alright.
I really like it, seen it many times, but haven't seen in for some years now. The Meltdown was only watchable because the characters are great, otherwise it was terrible. Haven't seen the third one, might see it one day, but I have very low expectations.
Similar to seeing Toy Story after all the sequels were made, this debut from Blue Sky Studios has a roughness in its animation that is still appealing all these years. Though it gets better as it goes along the dialogue and visual style make this lighthearted tale a solid film.