Just as nostalgia grows with each passing year of adulthood for the family trips one took as children (even the ones that weren't all that great), so, too, is there likely more than a tinge of sentimentality from viewers who grew up watching Clark and Ellen Griswold taking son Rusty and daughter Audrey on a disaster-prone cross-country vacation to amusement park Walley World in 1983's "National Lampoon's Vacation." Three respectable sequels followed—1985's "National Lampoon's European Vacation," 1989's perennial holiday mainstay "National Lampoon's Christmas Vacation," and 1997's "Vegas Vacation"—each of them starring Chevy Chase and Beverly D'Angelo. Eighteen years since the last Griswold sojourn, Clark and Ellen have stepped aside to make way for a return trek to Walley World with a now-grown Rusty (Ed Helms) and his own family. As written and directed by John Francis Daley and Jonathan M. Goldstein (making their feature helming debuts), the new "Vacation" stands on its own—or so Rusty tells wife Debbie (Christina Applegate) and sons James (Skyler Gisondo) and Kevin (Steele Stebbins) in a double-entendre-filled early scene.

Not at all a remake but a direct-sequel-cum-spinoff to creator John Hughes and director Harold Ramis' much-loved original, "Vacation" both pays tribute to its predecessors and, indeed, requires that audiences view it on its own terms. "National Lampoon's Vacation" may have been R-rated and not always in good taste (see the lonesome fate of Imogene Coca's Aunt Edna), but at its core was an affectionate story of a hard-working, eager-to-please father who tried beyond all reasonable means to give his family the attention and love he feared he hadn't been giving them the other fifty weeks out of the year. For this new "Vacation," Daley and Goldstein crank up the crude humor—and let it be known that it is very, very crude—but they still retain the underlying sweetness and authenticity that always permeated throughout the Griswold clan. Rude though it can be, the film also exemplifies how the tone and handling of potentially off-putting material is key when it comes to ensuring humor works. Make no mistake, it is very wrong, and yet more often than not so very right.

Every year, regional airline pilot Rusty packs up his wife and kids for a week at a cabin in Sheboygan, Wisconsin. Concerned that this tradition may be growing stale and desperate to better connect to wife Debbie and sons James and Kevin, he decides to recreate the family trip he took thirty years earlier to Walley World. Driving the bizarre, multi-featured, vaguely threatening 2015 Tartan Prancer—"the Albanian Honda," he reassures them—Rusty sets off from his hometown of Chicago, Illinois, en route to California. Naturally, everything that could go wrong does, sending the Griswolds on a journey to hell and back that may very well be the shock to the system they need to remind them of just how important they are to each other.

"Vacation" is gleefully crass, and "gleeful" is the operative word when it comes to a film that pushes much of its raunch and outrageousness to the limit. Not every gag hits its mark—a scene involving a cattle carcass is more stomach-churning than amusing, while another scene involving four state police officers converging at a "Four Corners" site falls flat—but far more of the movie works than it probably has any right to. Writer-directors John Francis Daley and Jonathan M. Goldstein have penned a screenplay that is bawdy yet smartly acerbic, episodic yet surprisingly cohesive. They, along with cinematographer Barry Peterson (2014's "22 Jump Street") and editor Jamie Gross (2014's "They Came Together"), prove remarkably adept at setting jokes up and milking them for optimal comedic timing. The ongoing trials and travails in their oddball car are sometimes nothing short of uproarious, with a remote control populated with horrific mystery buttons (there is even a swastika symbol on one of them) suggesting the vehicle was made under decidedly troubling pretenses. Along the way, they stop at a worrisomely scuzzy motel with surprises in the bathroom, a supposedly tranquil hot springs with not-so-rejuvenatory powers, Debbie's Memphis State College alma mater (where some long-buried secrets from her past come to light), and have a harrowing white water rafting experience guided by a depressed, newly dumped instructor (Charlie Day). All of these scenes and plenty more keep the laughs coming at a consistent clip, ensuring that the pace never lags. Even scenes that really shouldn't prosper, like a shockingly dark callback to the girl in the Ferrari (played by Christie Brinkley in the original, and Hannah Davis here), get away with it through sneaky visual flourishes—in this case, a plume of smoke in a rearview mirror.

Walking in the footsteps heretofore forged by Anthony Michael Hall, Jason Lively, Johnny Galecki and Ethan Embry, Ed Helms (2013's "The Hangover Part III") is endearingly game as Rusty Griswold, an earnest family man who doesn't know his family as well as he would like. As Debbie, Christina Applegate (2013's "Anchorman 2: The Legend Continues") hasn't had a film role quite this juicy in years. A long-underrated actress with a penchant for sharply funny line deliveries, Applegate brings welcome complications to a wife and mother who is gloriously imperfect and not always secure about the life she has found herself in. Rusty and Debbie's relationship is heartfelt and ingratiating; they grow to feel like a real couple, accepting of the love and messiness within their marriage. Rounding out the family unit, Skyler Gisondo (2014's "Night at the Museum: Secret of the Tomb") is innately likable as sensitive, introspective teenage son James, and Steele Stebbins (2014's "A Haunted House 2") is a kinetic force as hostile, foul-mouthed younger son Kevin, in urgent need of getting a taste of his own bullying medicine.

Leslie Mann (2014's "The Other Woman") doesn't get a whole lot to do as Rusty's sister Audrey, whom they visit in Plano, Texas, but a recurring joke in which her desires to have a career are routinely shot down by her steadfastly Republican husband, the sexy, well-endowed weather forecaster Stone Crandall (Chris Hemsworth), is comically pointed. As Stone, Chris Hemsworth (2015's "Blackhat") has fun with his physical image and the ridiculous aspects of his colorful character's voraciously flirtatious ways and nonexistent vanity. Regina Hall (2010's "Death at a Funeral") is a hilarious standout in her one and only scene as Debbie's confrontational gal pal Nancy, who doesn't take kindly to Debbie not clicking the "like" button on her Instagram photos. Newcomer Catherine Missal exhibits an undeniable spark as Adena, a cute girl whom James keeps running into during their vacation. Charlie Day (2014's "Horrible Bosses 2") uncannily embodies that of a talkative, gung-ho white water rapids instructor who takes the Griswolds out on the water just as his personal life is falling apart. Last but not least, it wouldn't be a proper "Vacation" movie without Chevy Chase (2015's "Hot Tub Time Machine 2") and Beverly D'Angelo (2008's "The House Bunny") as Rusty's parents Clark and Ellen, now the hosts of a San Francisco bed-and-breakfast. It is wonderful—and, yes, unavoidably nostalgic—to see them together again, but D'Angelo especially deserved more than the virtual walk-on she has received.

In pursuit of a modern-day take on family togetherness, "Vacation" barrels through boundaries with a savage but somehow still charming twinkle in its eye. This generation's Griswolds begin the film a little prickly and, in youngster Kevin's case, mean-spirited, but the longer the viewer follows them on their calamitous travels, the more real, identifiable and engaging they become. A self-deprecating reference to the constantly shifting actors who played Rusty and Audrey in the four previous films is deftly handled, but in most ways Daley and Goldstein play it straight even when things are at their most optimally absurd. Soundtrack cues, including Lindsey Buckingham's opening-credits linchpin "Holiday Road," Seals & Croft's "Summer Breeze," Seal's "Kiss from a Rose," and Harry Nilsson's "Without You," are also exceptionally woven into the story rather than simply arbitrary songs placed over scenes. Never losing steam even when a sporadic moment here and there doesn't click, the picture holds in reverence what has gone before while fearlessly and defiantly updating it for a 21st-century world. If fairly consistent laughter and more than a few uncontrollable guffaws is testament to how successful a comedy is, then "Vacation" stands next to "Spy" and "Trainwreck" as one of the more audacious the genre has seen this year. To echo Rusty's sentiment, it stands on its own, just as it should.