He wrote and directed 1998’s Safe Men, which played at the Sundance Film Festival, but it was filmmaker John Hamburg’s rewrite of the 2000 mega-hit Meet the Parents, and subsequent work with Ben Stiller, which brought him fame and industry clout, and his since formed the thematic spine of his work. That same heavy, mostly unleavened affinity for serial masculine debasement has charted the course of Hamburg’s career, and, for better and worse, it’s all over I Love You, Man, his first feature-length film behind the camera since 2004’s Along Came Polly.

I Love You, Man, an unhinged “bromance” about a betrothed young professional who embarks on a wild quest to find a best man for his upcoming nuptials, has the sun-ripened benefit of excellent casting, and the good sense to let its charming players carp and needle one another in loose, lived-in ways. It also feels willfully crude, though, with its relationships defined as broadly as possible, and in ways that don’t allow for a full-bodied exploration of the film’s rich conceit.

After Los Angeles real estate agent Peter Klaven (Paul Rudd) proposes to his girlfriend Zooey (Rashida Jones, above right) he’s stung and slightly unnerved to realize that his family’s teasing about him never really having a male best friend is at its core true. Not wanting to come across as overly clingy to Zooey or her friends, Peter tries to extend his social network by going on some “man dates,” several of which are arranged by his gay younger brother Robbie (Andy Samberg). He eventually meets Sydney Fife (Jason Segal), an oafish Venice Beach day-trader who expands Peter’s calendar of activities and allows him to reconnect to an avocational passion for music, even as his coarse manner helps create new problems between Peter and Zooey.

I Love You, Man‘s premise is modern, and brilliant; it could easily be used to delve substantively into the new, post-feminist (evolving? constricting? wounded?) male psyche. But the film eschews anything too complicated or dark, like either Peter not succeeding in his friendship quest, or Sydney turning out to have clingy, Cable Man-esque sociopathic tendencies of his own. The resulting laughs are the difference between pleasant surface engagement and a gratification to which you can return, something that feels built for the long haul, and rooted in reality. The cameo inclusion of Lou Ferrigno — who more or less acquits himself, as a home-selling client of Peter’s — feels forced, and as the movie wears on there’s massive drag in the second and third acts. With its watered-down, Fire in the Belly-type lessons, I Love You, Man is on some level the thirtysomething white dude equivalent of How Stella Got Her Groove Back, expect with a pinch more sex talk.

What most connects in I Love You, Man are the bits that aren’t afraid to not be funny to certain groups of people. Just as The 40-Year-Old Virgin wasn’t afraid to dis Coldplay or bizarrely name-check Kelly Clarkson, Hamburg’s movie summons up Dana Carvey’s decades-old “Church Lady” sketch, has some fun at the expense of The Princess Bride, and features a dog named Anwar Sadat. Of course, it also features a sequence with the projectile vomiting of chili. That’s the sort of lowest-common-denominator Hollywood concession that pays for the conceptual noodling, I guess, but it also makes I Love You, Man at least a bit less easy to love. (DreamWorks, R, 105 minutes)