Away We Go is a touching, funny, and nearly perfect comedy about a young couple expecting their first child and trying to sort out their place in the world. Unfortunately, it’s interrupted at frequent intervals by annoying cartoon comedy routines detailing the lives of families in the US and Canada, whom the main characters encounter as tryouts to determine what kind of parents they want to be. I would like to review the movie about the couple and ignore the grotesque caricatures, who mostly play like labored Saturday Night Live skits, but they insist upon themselves. The director is Sam Mendes (American Beauty, Revolutionary Road), who has such a gentle and tender touch in the film’s best scenes that we wonder where he was during the worst ones.

It opens with Burt (John Krasinski) and Verona (Maya Rudolph), who discover they are expecting in a most awkward manner — as pregnancy tests go, this is a new one. Burt is a bit gangly — a kid at heart, but not childish. He sells insurance futures, which he tries to explain, but it’s the kind of business where unless you’re buying or selling you’ll never need or want to understand it. Verona is an artist, patient and the more adult of the two, but this isn’t one of those sitcoms where a long-suffering wife puts up with her immature man-child husband. They have real conversations and real concerns and genuinely love each other.

And then begins the shtick. The story is divided into six episodes. Two of them are good. Four of them aren’t. It’s dispiriting that the worst segments feature the likes of Allison Janney, Jim Gaffigan, Catherine O’Hara, Jeff Daniels, and Maggie Gyllenhaal.

O’Hara and Daniels play Burt’s parents, Gloria and Jerry. Burt and Verona have moved to Colorado to be near them, only to learn that the elder couple plans to move to Europe — for two years! Gloria and Jerry are wacky eccentrics, collecting expensive Native American pseudo-art to honor the nation’s “indigent” peoples. Or is it “ingenious”? We’re supposed to be amused, but Burt’s parents have such thoughtless disregard for their son, his girlfriend, and their unborn child that we’re irritated instead. “We could get someone else to be the grandparents,” Burt jokes. I think he should put out an ad and start fielding offers.

The departure of his parents sends Burt and Verona reeling. They never really wanted to live in Colorado, so they embark on a trip to find a new place to live, stopping to visit friends, family members, and old acquaintances who might become their new neighbors. Their first stop is Phoenix, Arizona, where they encounter an even more unpleasant set of parents. It’s impossible to see Allison Janney or Jim Gaffigan’s names attached to a film without smiling, but all enthusiasm ends when we meet their characters: Lily, who shrieks insults about her kids within earshot, and her husband Lowell, a miserable misanthrope. I wish their kids the best of luck — they’re gonna need it.

More abrasive still is a visit to Madison, Wisconsin, where we meet LN (pronounced “Ellen”), played by Gyllenhaal. The first shot of her tells us all we need to know about her child-rearing philosophy, and all we need to know about the film’s opinion of her philosophy: LN, a college professor, stands in her office with a baby feeding from her breast and her four-year-old son, it appears, feeding from the other. A-ha! She’s a granola, hippie, wheat-germ, smothering, new age fruit loop. She doesn’t believe in strollers. She doesn’t believe in boundaries either; her family sleeps in a communal bed. She’s not a character with eccentric parenting beliefs, she’s a walking punch line about eccentric parenting beliefs, and it’s not a good punch line.

In Montreal, Tom (Chris Messina) and Munch (Melanie Lynskey) seem perfect! They have a large family of adopted kids, and Burt and Verona are ready to move there on the spot. Could you guess they’re not as perfect as they seem? This couple’s troubles are revealed abruptly in a scene of queasy moroseness that ends with the husband and wife in a grotesque heap of despair.

There are two visits where the characters play like people, perhaps because they involve individuals who aren’t required to be specimens of parental dysfunction. One is Verona’s sister, Grace (Carmen Ejogo), and the other is Burt’s brother, Courtney (Paul Schneider). They aren’t reduced to types. Their family bonds feel authentic. When they speak, it’s about something.

And then there’s Burt and Verona, and the sublime performances of Krasinski and Rudolph, who generate such warmth that I smiled a mile wide. Their relationship rings true where most of the others feel stagy and affected. The film ends on scenes between them so utterly good that I almost forget its previous inconsistencies and indulgences. I have to recommend Away We Go on the strength of these characters; if Mendes and writers Dave Eggers and Vendela Vida had brought the other characters down to the same human level, it might have been great.

Watch a trailer for the movie here: