Like switching horses mid-gallop, the leap from television comedy to the movies is notoriously treacherous. And when most alumni of “Friends” and “The Office” are taking headers into the dust with regularity, the pedigree behind “The Brothers Solomon” bodes a rough landing. Sure enough, the combined experience of canceled cult shows and “Saturday Night Live” can’t outweigh sporadically funny material doomed by a self-destructively flat tone, though tracing exactly why proves interesting.

As the trailers have blared all summer, “The Brothers Solomon” stars Will Arnett and Will Forte as two fat-heads trying to produce a grandson for their ailing father. Raised in isolation at the North Pole, John and Dean Solomon are well-intentioned simpletons, lacking social skills and common sense. They still bed down in sleeping bags like 12-year-olds; when they hear their father is sick, they stop on the way to the hospital to dispute a fine at the video store.

After some ham-handed forays into dating, the two ninnies hire a surrogate mother Janine (Kristen Wiig, a good sport). “The Brothers Solomon” is mostly about the pair’s boisterously bizarre attempts not to screw up the arrangement, as they expose near-extraterrestrial levels of naïveté. Janine’s intimidating boyfriend (Chi McBride) and John’s disastrous flirtation with an attractive neighbor (Malin Akerman) provide two added obstacles.

The lead actors are the most obvious veterans of the comedy trenches. On the exquisitely crafted and short-lived Fox comedy “Arrested Development,” Mr. Arnett was a triumph of overweening idiocy as the beyond-prodigal son Gob Bluth. His justly praised work led to turns in films such as”Blades of Glory.” Mr. Forte, who wrote the screenplay for “Solomon,” and Ms. Wiig are more recent arrivals on the big screen, hailing from “Saturday Night Live,” that old, shrill man of TV comedy.

The two Wills comport themselves with respectable fresh-faced stupidity, but it’s director Bob Odenkirk whose experience leaves the biggest imprint on “The Brothers Solomon.” In the late 90s, Mr. Odenkirk co-wrote the sketch comedy “Mr. Show,” one of the cultest of cult programs, with David Cross (another “Arrested Development” alum). Each episode was a take-it-or-leave-it blast of twisted parody, Monty Python lunacy, and often discomfiting edge, with the ramshackle skits and bits absurdly strung together.

“The Brothers Solomon” joins the string of little-seen oddities that Mr. Odenkirk has directed since “Mr. Show” and bears traces of its misunderstood style. While “Solomon” looks like another pratfall down the romantically challenged road of male juvenilia, the deadpan tone and the derangement distinguish the film from the usual goofing off. Good examples include Dean’s truly unexpected, unnerving kiss on a first date, or the pair’s demonstration of the rugged trunk they’ve repurposed as a crib for their baby-to-be, or even the dicey (and very late-90s) tweaking of race stereotypes through the character of Janine’s boyfriend, who is black.

Yet the movie’s downfall is that Mr. Odenkirk and his cast appear intent on hard-selling all the wrong jokes. An impatient, maybe even contemptuous edge to some of the material suggests the filmmakers’ awareness of what they’re doing, but deadpan idiocy sometimes comes off as just dumb. That’s the great danger of the film’s literally off-beat approach, which soft-pedals brilliant little surprises but cranks up the volume for worthless gags. (“Solomon” even takes the well-worn joke of a hackneyed ’80s song — this time it’s “St. Elmo’s Fire” — one ludicrous step too far.)

“The Brothers Solomon” might be following some recipe for later cult rediscovery by connoisseurs of the recalcitrant. As intriguing as that prospect might be, at the end of the day the movie gets very mixed results out of the paces of its silly caper and the reliably concussed grins of its capable stars. Even for a comedy that contains the most masterful and exquisitely timed sky-banner joke ever committed to film, fans of “Mr. Show” or “Arrested Development” may be better off dusting off the old box sets than braving “The Brothers Solomon.”