In the interest of transparency, I should preface this by stating that I've only seen the first Ice Age movie and I've seen it only once...at the dollar theater and have had no interest in seeing it or any of the other Ice Age movies again.
Ice Age: Continental Drift starts with Scat trying to do what he does with acorns and very comically leads to the splitting of the continents (its science). Then we get n update on the lives of our furry friends Manny, Sid, and Diego. Manny is still married to Ellie but they now have a daughter named Peaches. Sid is still the same Sid and Diego is still falling victim to his stupidity and that of his long lost relatives. When their part of the world is separated, Manny and his buddies are separated from his family and the rest of their animal friends. Stuck on an iceberg they come across another iceberg that looks like a pirate ship and is, okay, it's a pirate ship lead by Captain Gutt, a prehistoric gorilla. They manage to escape capture, steal Gutt's ship, and after another encounter with Gutt manage to find their way back home to (you guessed it) have a final showdown with Captain Gutt and his bumbling crew.
Ice Age: Continental Drift is the kind of film the kids will like because enough happens to keep them interested and they can laugh at just about everything in it and it's entertaining enough for grownups to sit through with them. However, even having not seen the other movies, I'm pretty confident in saying that if you've seen the others, you've already seen this one. It doesn't defer from the formula of the children's movie franchise which is keep them hooked with same predictable story with the same jokes and make the characters likeable enough so the kids want to come back in couple of years. Manny is the John McClain of kids' films; always in the wrong place at the wrong time.
The highlight of the film is Scrat, the whatever it is that is always after that Acorn. I could watch and hour and a half of just him doing just that. It's the best part of the film and he's the most likeable character. Think about the trailer for Ice Age: Continental Drift, did you laugh more at the one with just Scrat or the one that told you what the movie was about? I rest my case.
I give Ice Age: Continental Drift 7 stars out of 11.