Everything is at an evolutionary dead end in this animated sequel, taking place again in frozen prehistory, now explicitly threatened by global warming and flood. What look like rough-sketch versions of buffaloes and rhinos have the swollen disproportions of plastic toys put in the microwave. Beta-test beavers and deer sport horns on their noses; mammals have been mashed up with reptiles in a pre-Precambrian remix of feathers, fur, and scales; every creature (there are no humans) save one can talk, and mass extinction is on the tip of their sundry tongues. Leading the animal exodus to high ground are the same three amigos from 2002: a morose, last-of-his kind mastodon (voiced by Ray Romano); a saber-tooth cat (Dennis Leary) with all the personality of the Jaguar hood ornament he resembles; and a hyperactive spazz of a giant sloth (John Leguizamo), who’s got way too much personality—he’s practically toxic with the stuff.

Chris Wedge, who devised the original look for Ice Age (3-D fur in the foreground, flat Warner Bros.–style cartoon backdrops), has departed for the sequel; and the voice talent sounds pretty blasé about the reunion. (New are Queen Latifah as a mixed-up mastodon and Jay Leno as a huckster armadillo selling alarmist weather forecasts.) I’d say the fur looks better this time, close to the level of Monsters, Inc., but the writing still lags far behind Pixar. Friendship, loyalty, and herd family values—OK, OK, we get it, now could we get back to Scrat?

Interspersed with the dangerous (but not too scary) journey to safety, kid-pleasing slapstick, and mastodon courtship rituals are the silent little squirrel-rat-raccoon-fox creature’s efforts to obtain his beloved acorn. As before, he’s the best thing about the movie, providing valuable lessons for your children—not about courage and trying new things, but about when it’s appropriate to climb up your own tongue if you’re hanging from an icy cliff by your tonsils; or under what circumstances it’s OK to retract your head into your body. He even does kung fu this time. Stick around through what seems like the movie’s final fade-out—sweet deliverance for parents, with time still left on the parking meter!—for Scrat’s heavenly adventure. The Ice Age series may be cooling down, but he’s just warming up.