I'll be honest, I wasn't expecting much from this film. In fact, I was pretty sure that it was going to be the funny bits of the trailer strung together with a half-assed plot and some decent animation. While the plot is, indeed, rather slight, I found myself very pleasantly surprised by the movie.
The characters are very endearing. The movie takes time to get the audience comfortable with them so that when there is friction between them, no one character comes across as being an asshole. Chris Rock, Ben Stiller and Jada Pinkett-Smith are funny enough (as a zebra, a lion and a hippopotamus, respectively), but one of the most charming elements of the film is - surprisingly enough, as I normally loathe Friends cast members - David Schwimmer's giraffe, both in terms of his delivery and the animation. Even if there is nothing else funny going on in the film (which is rare), the contortions that his character ends up in are funny enough for a chuckle.
The penguins were pretty hilarious too. There must be something about digital avians in kids' movies that strikes the funnybone, as there were hysterical birds in Finding Nemo and Peter Pan as well (the latter possibly being the hardest I've laughed at an animated character ever).
The movie is good-natured and has a leisurely pace, with nice appearances by Sacha Baron Cohen and Cedric the Entertainer as lemurs (I want a lemur!). Even Hans Zimmer and his Media Ventures slaves (there are three additional composers credited) provide an okay score, which for them is a huge achievement. It is interesting to note, however, that the real standout musical moments belong not to Zimmer or his cronies, but to Thomas Newman, whose American Beauty theme is used to great advantage in a dream sequence, and Elmer Bernstein, whose National Geographic theme makes a welcome and oh-so-fitting appearance.
A truly entertaining picture.