The best part of “Between Two Ferns: The Movie,” a semi-amusing, Netflix-produced addendum to the popular Funny or Die web series, is the closing-credits blooper reel. That might sound like a backhanded compliment, which means it’s still nicer than anything that comes out of the mouth of Zach Galifianakis, the tetchy, nervous, endearingly unpleasant host who spends every episode of his mock talk show, “Between Two Ferns,” firing deadpan insults and non sequiturs at his guests.
It’s all a joke, of course, and a pretty good one: The slovenly emcee gets to roast a few famous people, who prove themselves to be excellent sports as they register their contempt. On past episodes, the guests’ improvised responses have tended to vary; there have been appalled silences (Natalie Portman), grumpy, gum-chewing sighs (Brad Pitt) and some combative rejoinders (Barack Obama). Sometimes the show of discomfort comes off a bit strained: Would a Hollywood A-lister really just sit there and squirm in the face of so much abuse?
Which is why the blooper reel in the movie feels so welcome. It’s a pleasure to see Brie Larson respond to a grossly inappropriate question with uncontrollable laughter rather than stone-faced silence or to hear Galifianakis break character mid-line reading and burst into chuckles. They’re actually enjoying this! All of which I mean as a compliment to “Between Two Ferns” the show, which sustains such a persuasively nasty, snarky, cringe-inducing mood that it’s a relief to be reminded that it’s all just a clever put-on.
Directed by series creator Scott Aukerman (who co-wrote the screenplay with Galifianakis), “Between Two Ferns: The Movie” is a put-on too, though not nearly as clever. Like some of the feature-length spinoffs of old “Saturday Night Live” sketches that proliferated in the ’90s, it feels like a padded version of a bit that was a lot sharper in five-minute increments.
The premise is that a documentary film crew is following Zach around the crummy public-access TV station where he works, capturing how that “Between Two Ferns” magic happens. Will Ferrell, one of the founders of Funny or Die, turns up every so often to boss Zach around. We also meet the members of Zach’s shoestring crew, including his loyal No. 2 (a game Lauren Lapkus), whose many tasks include watering the signature potted plants that adorn the set.
Speaking of water, a pipe bursts and the studio is flooded, interrupting a pretty funny segment with Matthew McConaughey (“Of all the things you can win an Oscar for, how surprised are you that you won one for acting?”) and forcing Zach and his crew to take their show on the road. And so they make their way cross-country, tracking down celebrities gullible enough to be interviewed (Jon Hamm) and at least one who has other objectives in mind (Chrissy Teigen), all while hitting the familiar beats of a road-movie plot that goes nowhere fast.
Amid the third-rate hijinks and shabby mock-doc stylings, you always want more of “Between Two Ferns” itself. There are some characteristically funny interview excerpts here and there: Tessa Thompson, Hailee Steinfeld, Keanu Reeves, Tiffany Haddish and a priceless Benedict Cumberbatch are among the lucky celebrities who wind up in the guest’s chair. But most of those bits are folded into zippy highlight montages — a device that saps the comedy of its duration, the sense of entrapment that is its most crucial, cringe-inducing element. Well, that and Galifianakis, who once again mocks himself to scowling, Doritos-smelling perfection.
Running time: 1 hour, 25 minutes