Although it's set on the same frozen continent, Happy Feet Two is worlds away from its predecessor.
Mumble (voiced by Elijah Wood), the first film's penguin protagonist, has gone from toe-tapping outcast to colony leader, but his son Erik (Ava Acres) is both tone deaf and fumble-footed, unable to sing or dance his way into the heart of a potential mate.
When the crumbling Antarctic coast traps the Emperor flock in an icy prison, father and son set off to enlist the help of the distant Adelie penguins, an obstreperous elephant seal, and a wayward seabird named Sven (Hank Azaria), whose Scandinavian self-empowerment slogans transfix his flightless brethren.
It's familiar enough not to spook fans of the (highly profitable) first, but Happy Feet Two branches out beyond prefab coming-of-age stories and gimmicky pop-song set pieces. Its dense, deftly woven fabric is made up of many threads, including a parallel subplot in which a couple of krill named Will (Brad Pitt) and Bill (Matt Damon) are provoked to existential crisis by the sight of a whale swallowing their undifferentiated swarm-mates en masse. Director George Miller and his three cowriters leave no pun unturned as their invertebrate "Bob Hope and Bing Crosby" try to claw their way up the food chain, a long shot with odds of roughly one in a krillion.
The computer animation by Australia's Animal Logic studio has improved dramatically, which has less to do with the now-mandatory upgrade to 3D than with an increased command of texture and light. When a solitary krill drops into an underground cavern illuminated only by his dim bioluminescence, the disparity between his fragile glow and the surrounding dark is enough to make you catch your breath.
Miller still indulges a weakness for on-the-beak song choices, like Janet Jackson's "Rhythm Nation" to express tribal solidarity, but he casts his net a little wider; instead of the Beach Boys for an aquatic montage, it's the Rivingtons' "Papa-Oom-Mow-Mow" this time around. Alecia Moore, better known as P!nk, contributes a middling original ballad as well, taking over the role of Mumble's mate from the late Brittany Murphy. Robin Williams hasn't been persuaded to tone down the ethnic caricatures of the Latin lover Ramon and the soul-man shaman Lovelace, but at least there's less of both.