Toilet and s3x humour fest This is a classic Apatow movie filled with toilet humour, jokes about m.sterbating, and kids saying "rude" things for shock value etc. Essentially, the plot features an unattractive pothead, loser bum who turns good when he accidentally "knocks up" a girl out of his league who then leaves him. These two dysfunctional people got pregnant while drunk, she knew he was a pothead and she still expected him to step up and be a "father"?
Then we have the future to aspire to as a family - shown here by Apatow's IRL wife and nepotism kids - acting as a dysfunctional family with Paul Rudd, as the once again classic Apatow henpecked man who deserves to lie to his wife and have "fun" gambling and drinking with his friends while she is at home with the kids.
The kids could have been replaced by other better child actors, but that wouldn't meet the goal of getting Apatow's kids into acting now would it? Kids he was happy having swearing in his movies along with his wife talking about m.sturbating another man.
To summarise, since this review needs 600 'characters', if you've seen one Apatow film, you've seen them all.