Penguins are awesome. Animated penguins that are nearly tangibly fuzzy are awesome. Everything was pretty and delightful to watch, especially when blown to humungous proportions on the IMAX screen.
But the story? Eh. Didn't care. Penguins have heart-songs and fall in love with another penguin's music; little Mumble can't sing so he's SCREWED and must go off on an epic journey to prove his true penguin heart is true, and what better way to express this to have espresso-jitters in your toes? Fine. Having all the penguins singing songs by Elvis and Tom Jones was dull and tired; it would have been so much better if the creator had hired a songwriter to make new tunes. This could've been a penguin musical extravaganza! Instead it's just a rehash of love songs that appear on compilation CDs sold on midnight infomercials.
I also appreciate the thought behind the heavy-handed environmental and religious commentary, but this is a kid's movie! One message about accepting differences is enough. The multiple themes the director was trying to weave together led to a tangled knot and dragged the movie down. The second half is very, very, slow. You'd get to a point and think "Ah, we're wrapping up for the ending," but the movie chuggered on like the oil tanker that ignorantly plowed through the Antarctic landscape.
But man, those penguins were cute.