Unlike most middle-aged men, Judd Apatow can afford a whole garage of Camaros and Mustangs. So, it makes sense that his mid-life crisis would manifest not with a youthful car buy, but by splurging on the production of a new movie.

"This is 40" is that movie – a semi-sequel to "Knocked Up" and Apatow's personal take on the foibles of family and getting old. It's also scattered, emotionally confusing, inappropriately funny and borderline heartfelt – which sounds a lot like a mid-life crisis to me.

"40" revisits Pete (Paul Rudd) and Debbie (Leslie Mann) just as both of them hit their 40th birthdays. They both have independent, fulfilling (but not perfect) jobs and juggle the responsibility of raising two daughters (Apatow and Mann's real-life offspring, Maude and Iris). But, they're not happy, and it quickly becomes apparent that their money situation – among other things – isn't so hot. This serves as the catalyst for all sorts of turmoil, from extended family squabbles to full-on relationship upheaval.

First I have to express my amusement (and concern) that, according to Apatow at least, humor seems to be genetic – and contagious. Everyone in "40" spouts off their one-liners with the same "I'm not trying to be funny, this is just how I talk" wit. Pete and Debbie, their friends, doctors – even the kids – keep pace with Apatow's style. I'm not coming down on the humor, but I did find its widespread usage distracting, and ultimately it detracts from the realism of what they're all trying to accomplish. It's funny – very funny at times – but personally, if I talked to my mother the way Charlotte talks to Debbie when I was younger I'd have gotten smacked (history backs this up).

Much like the one-size-fits-all humor, the whole family dynamic also trips over into the world of the contrived. It tries too hard at the outset to make itself relatable by cramming all of the "getting old" greatest hits into the first half hour. Pete's been secretly taking Viagra, Debbie insists she's still 38 (or is it 36?), there's no mystery in the couple's relationship (as evidenced by the regular invasion of bathroom privacy, among other things) – the list goes on.

Without the substance that comes later in the movie, the characters' interactions during this intro period seem too artificial. No person or family experiences every single one of these issues – or if they do, they're not all dog-piled on top of each other like they are in "40." It's just not believable enough for the audience to empathize with, so yes, while the introduction is funny and lighthearted, it's essentially killing time until Apatow gets to the real stuff.

And really, I have no idea what the rush is. "40" clocks in at 134 minutes – plenty of time to stretch things out. Instead, Apatow fumbles through sections of funny and serious, finally hitting his stride way too late in the over-two-hour runtime.

The serious side of the journey is spiced up by a colorful whirlwind of friends and family, who pick up the humor torch with entertaining (and chaos-inducing) asides. Jason Segel, Chris O'Dowd, Megan Fox (who should be cast as minor talent only from now on), Albert Brooks, John Lithgow and especially "Bridesmaids" favorite Melissa McCarthy bring some semblance of awkward balance to the tone as Pete and Debbie's money, work and family troubles come to a head.

With its numerous and messy obstacles, "40" has an almost insurmountable amount of work ahead of itself to wrap things up. It gets there (it does have plenty of time left to slog through), but with all of the effort of salmon swimming upstream. The resolutions pile on one by one in an endless string of false-start endings, and when things finally do clear up, it leaves the audience wondering what all the fuss was about to begin with.

I feel bad trouncing "This is 40." It is funny (if uniformly so), and it's obvious a lot of heart is behind it. The problem is it never has a chance to peek through the clouds of punchlines and subplots. With a little more refinement (and a half hour more left on the cutting-room floor), "This is 40" could have been that shiny movie Camaro Apatow was after.