Jordan Fischer critiques the trajectory of Judd Apatow's career:
This Is 40 seems to be almost the definition of a screenwriting non-challenge — it's so thoroughly The Judd Apatow Story that for the third movie in a row, he's cast his actual wife and actual kids as thinly veiled caricatures of his actual wife and actual kids. (The always-appealing Paul Rudd returns as a somewhat handsomer Apatow.)
Now, don't get me wrong; I actually find Leslie Mann — Mrs. Judd Apatow — funny and talented. And yes, his kids, like many kids, are cute. But his path-of-least resistance casting and thin plotting seem to point to an increasing solipsism in his work; a diminishing curiosity about anything in the world that's not right in front of his nose.
Megan Daum also finds the film wanting:
[I]n “This is 40,” Apatow seems to be really trying to say something profound about marriage and the difficulties of getting older. The problem is it’s almost as if he’s a fourteen-year-old imagining what it’s like to be forty (“that’s like, really old—but at least you can have nice cars!”) and the result is that the movie is a stunning misrepresentation of life at any stage.
The Dish 