Once again, as in the first Ice Age, wooly mammoth Manny (voice of Ray Romano), sloth Sid (John Leguizamo), and saber tooth tiger Diego (Dennis Leary) set off on a journey. This time, they have to lead their friends out of the valley before the ice melts and it becomes flooded.

Along the way, Manny wonders if mammoths are about to become extinct because he seems to be the only one left, until he meets Ellie (Queen Latifah), a mammoth who thinks she is a possom. Sid meets up with some miniature sloths who think he is their Fire King. And all of the characters face predators and other obstacles as they try to beat the water to the edge of the valley. And every now and then we get to see the continuing saga of Scrat the prehistorical squirrel and his Sisyphus-like quest to get and keep an acorn.

Even by the low standards of sequels (it’s fair to expect at least a 30% drop-off in quality), this is a disappointment. There are brightly funny individual scenes, especially the “Fire King” encounter (though it seems to have been taken straight from one of the Hope and Crosby “Road” movies — or, come to think of it, all of them), but it doesn’t have the power or imagination of the original. Instead, itt has a cluttered plot with a formulaic mix of potty humor, mostly kid-appropriate scariness, and some encouraging lessons about responding to fear and the imprtance of family.

The primary relationship issues between the three leads were resolved the first time around and the new characters don’t add much interest or do much to propel the story. On the contrary, they serve as a distraction, especially the resolutely un-cute and un-cuddly mischievous possums. When their very un-possum-ish sister natters about her feelings as though she was in the middle of a Dr. Phil show instead of a life and death struggle to save members of her group, it is less likely to be amusing for children and their parents than annoying. A well-designed Busby Berkeley-style dance number to the Oliver! song “Food Glorious Food” is sung by vultures hoping that the characters we are rooting for don’t make it, so they can feast on the “putrid” meat.

This last example is a good indicator of the movie’s primary problem — an uncertain sense of its audience. A crowd old enough to recognize references that are 40 and 60 years old? A crowd old enough to find some dark humor in having vultures sing about how excited they are that animals we have just spent most of a movie with are going to die so they can eat them? As Ben Stein said so memorably in Ferris Bueller’s Day Off, “Anyone? Anyone?”

Parents should know that the movie has some tense and scary moments with characters in frequent peril. Predatory fish with many very sharp teeth chase after the characters. At least one character is killed (offscreen and discreetly) and another has a near-death experience. There are discussions of possible extinction. Characters use some crude and insulting language (“idiot,” “moron,” “crap”) and there is some potty humor. An odd near-death visit to Heaven may be disturbing to some audience members.

Families who see this movie should talk about how we recognize and deal with our fears. Why were Ellie’s feelings hurt? How do you feel about the way Ellie and Manny resolved their argument about which way to go? Several characters in the movie were lonely. How can you tell, and what did they do about it? What does it mean to be “the gooey, sticky stuff that holds us together?” And they should talk about endandered species and efforts to protect them. Families might also want to learn more about wooly mammoths and other ice age animals.

Families who enjoy this movie will enjoy the original Ice Age as well as The Land Before Time and its sequels.