I was hoping to like this movie, despite its much-discussed similarities with other, perhaps better, films. It had quite an impressive voice cast, after all. Sadly, there was very little "there" there. My first reaction to the movie (well, after thinking it was cool that Iggy Pop was going to be getting some checks out of their using "Wild Child", albiet a cover version, over the closing credits) was that it seemed like there were big chunks which had been edited out at the last minute. The film ran an hour and a half, but it felt like there had been a 2-hour movie cut down to what was on the screen. A prime example of this was when the "rescue party" ended up in the sewers, and met the alligators. The alligators argue about how to get them down to Battery Park, they eventually agree, and ... fade to black ... next thing we know, it's the following morning, the alligators are totally gone/forgotten and they're on the docks looking for the lion kid. I know you can't ask for too much continuity in a animated feature, but come on! There were several other points where stuff just suddenly "appeared" which was screaming for some establishing scenes. No such luck.
As far as that big-deal voice cast ... it was mostly wasted. If you're going to use "name" voice talent in an animated feature, it really helps if the casting brings something to the characterization that wouldn't be there if one was using "generic" voices. As much as I was expecting a "Make it so!" out of Bambi's dad in Bambi II, Patrick Stewart lent a certain gravitas to the role ... I kept wondering why they bothered with paying Keifer Sutherland and Janeane Garofalo for their roles, which were so flat as to have been adequately filled by "C list" voice talent. Not that everybody was wasted here ... Jim Belushi as Benny (the squirrel) and Eddie Izzard as Nigel (the koala) were brilliant, and could pretty much each carry their own animated film. Also, William Shatner did a great scenery-chewing turn as the mad Wildebeest leader and I was able to recognize Patrick Warburton (Kruk in Emperor's New Groove) just from his voice as Shatner's character's main flunky.
Again, there were gaping holes in the "logic" of the story, but that's not necessarily a fair slam at a kiddie animation project, but, still. On the plus side, there were "continuity" elements that one would not necessarily expect (like the ship they went to Africa in having paint scrapes along its side when they were leaving, left over from a collision in the NYC harbor), which might not even have made it into a "real" movie. Also, and this was subtle, the volanic eruption towards the end of the movie looked (to me at least) as a very close homage of the one that Scientology used to have on the TV commercials for Dianetics ... I don't know what sort of "in joke" that might have been, but it did give me a chuckle.
Anyway, if you don't have kids dragging you off to the movies, this is one you can safely skip.