"All talking, all singing, all dancing." With penguins. How can you go wrong? There's some amazing animation in this one,and the voice work is all good. Robin Williams gets all the best jokes playing two different roles, but that might be because he made them up as he went along.
Penguins, it seems, can sing, and they all have to find their "heart song." Mumbles can't find his because he can't sing. He can only dance, which is un-penguin behavior. Eventually he gets blamed for the fish shortage and even gets banished from the penguin colony. He sets out to find the real reason for the food shortage, and does. There's a green message and a happy ending that it would be nice to believe could really happen.
The movie pokes fun at those who believe being different is wrong and at organized religion (this should have caused some trouble, but I don't know if it did; maybe I'm wrong about the fun-poking). It was a little too long, but it's great to look at even in the slow stretches. Nicole Kidman and Hugh Jackman sing. Brittany Murphy sings, too. Maybe you won't consider that a plus, but I thought she did fine. And anytime you have penguins singing Beach Boys songs, you have a winner. Check it out.