As an admitted old fogy, I hated this movie, an ultra-raunchy, raucous gross-out comedy that’s like a “Hangover” with time-travel replacing mere alcoholic stupor. But if you’re among those who enjoyed that picture—or the other similar Apatow-inspired slob farces that have proliferated in recent years—then “Hot Tub Time Machine” is for you. (What that says about your taste is another matter.)

It begins by introducing its four “heroes.” There are Adam (John Cusack), a sad-sack insurance salesman whose girlfriend has just moved out of his pad, and his super-geek nephew Jacob (Clark Duke), who lives in his basement playing video games because his mom’s moved in with a boyfriend. Then there’s Nick (Craig Robinson), a beefy fellow who gave up the dream of a singing career to get married and is now stuck with a dead-end job in pet grooming and (as it’s later revealed) a wife who’s cheated on him. And finally Lou (Rob Corddry), a loudmouth, nasty lout whom the other two older guys rightly refer to not as their friend but their “a**hole” after he apparently tries to kill himself.

To keep Lou from going that route again, Adam and Nick take him off to a ski resort where, during the eighties, they’d had great times they hope to resurrect, and Jacob tags along. The place is now a dump, of course, and the guys seem poised to waste a weekend until their broken-down, moldy hot tub (complete with the corpse of a coyote) is magically transformed into an invitingly bubbly contraption that takes all four of them back to the Reagan era.

No explanation is ever afforded, of course; “Back to the Future” used a mad scientist, but here the approach is more like 1998’s “Pleasantville,” where a TV inexplicably served the same function as the tub. But while that movie was an essentially sweet, if satirical, take on nostalgia, this one is a foul, cynical send-up. It lacks the slightest semblance of logic—the guys decide, based apparently on “Star Trek” references, that to get back to 2010 they have to repeat what they did in the past, but that train of thought isn’t followed long, and soon the script goes off in random directions, many of them involving a snooty bunch of frat-boy type ski police and a surly one-armed bellboy (Crispin Glover), who proves much more friendly in his old two-armed form (a cruel running joke has Lou anxiously awaiting the accident that will dismember him). Its “surprises” aren’t that at all—a revelation about Jacob’s paternity will be obvious to any sentient viewer twenty minutes in—and the big ending is like a bad SNL sketch, and feels unearned. And when the script veers into seriousness or sentiment, you only hope that it’s intended as a spoof of really bad writing–though one doubts that’s the case.

And much of the humor is of the scurrilous or scatological sort—the picture begins with an excrement gag, includes two scenes of projectile vomiting, one extended blow-job joke, plenty of nudity and noisy scenes of intercourse, lots of slapstick violence, some typically adolescent gay humor, and reams of off-color dialogue. Dumbing itself down for an audience it apparently has little respect for, the script confuses the eighties with the sixties and seventies, and employs allusions to bad movies (“Wild Hogs,” “The Butterfly Effect”) as points of reference, along with the inevitable insertion of a slew of pop songs from the period. The result is a particularly chaotic example of what can be called an arrested development movie—one aimed at viewers who, whatever their chronological ages, pretty much stopped intellectual growth around 13.

The cast certainly doesn’t help matters. Cusack is simply dull, and disappears for long stretches, while Robinson is, as usual, incredibly stiff. Duke is bland, and though Glover is energetic enough, one wonders why he changes so little over twenty-five years. (We get glimpses of the three pals as teens, but not him—in fact, you might wonder whether the movie would have worked better if the young actors we see so briefly had actually taken over the roles permanently in the eighties scenes, rather than having the “stars” continue the parts.) Chevy Chase appears to no effect as the kooky repairman who acts as the equivalent of Don Knotts in “Pleasantville.” But the real killer is Corddry, whom some people apparently find hilarious, but why is a mystery to me. He certainly makes Lou convincingly obnoxious and loathsome, but that’s more irritating than amusing. Corddry is like David Koechner without the twisted mouth, and much less funny.

Visually “Hot Tub” looks pretty crummy, but that’s less the fault of Jack Green’s cinematography or Bob Ziembicki’s design, Jeremy Stanbridge and Kelvin Humenny’s art direction, Johanne Hubert’s set decoration and Dayna Pink’s costumes than it is of Steve Pink’s manic but undisciplined direction and the messy editing by George Folsey, Jr. and James Thomas. The visuals mirror the content.

And that content will be the problem for some of us. Vulgarity is commonplace in today’s comedies, of course, but it’s rarely gone so far as here, and such excess can be more disgusting than amusing. If you enjoy this sort of thing, you’ll probably find immersion in this “Tub” a pleasurable experience. The rest of us will wish we’d been able to turn back the clock 99 minutes and avoid this movie altogether.