Whether you're a fan of the first three or just a fan of the first one, do NOT watch "Continental Drift."
The other movies were great because they had charm, lovable characters, and jokes to make kids and adults laugh. But this movie seems to have forgotten that they have an adult fanbase and settled for cheap jokes that only a hyper little kid would find funny.
The characters we've been following suddenly aged a lot. Remember Peaches the baby? Now she's a teenager. And, because nobody is allowed to be single, they gave her a boyfriend -in the form of a pathetic little dork. He has a crush on her but she wants to go out with a bad boy, and the writers assume that this is enough to make us feel sorry for him. Actually, it comes off as if he doesn't care about her feelings and wants to hook up with her more than he wants her to be happy. She makes friends with the "wrong crowd" but eventually gets together with him because he manipulated her enough to make her feel bad for him. Give me a break.
Then there's the other, more important plot about the family being separated and trying to get back together again. The annoying thing about this is that the two female characters they've introduced in the franchise are suddenly miles away, while the male characters we started off with (and Sid's grandmother) are staying with us for most of the movie. But don't worry, the audience won't notice if we just replace them with one new female that we know nothing about, right?
And this new female is just a female version of Manny who will become Manny's girlfriend because they can't have any single guys. Except for Sid, because he's a loser.
The rest of the plot bounces around all over the place like a kid on sugar-high. There's something about pirates and escaping but it's kind of hard to follow, and the film keeps jumping from this to the side-plot with Peaches and her stupid boyfriend.
So what was the point of this movie? There wasn't a point to it. With the first movie, the point is getting the baby back home (and making new friends), in the second one the point is escaping the changing environment (and making new friends), with the third one the point is dealing with the neighboring dinosaurs (and starting a family.) This one may have had some point about staying with your family, but I felt too lost.