Just to make sure that it's fun, Hot Tub Time Machine throws in a pile of pop-culture references and a whole lot of raunchy humor. Nick, Lou and Adam are formerly best friends who have drifted apart. Nick (Craig Robinson) is married, with a job in a dog spa: not exactly the music career of which he once dreamed. Adam (John Cusack) has been recently dumped by his girlfriend; the parting was not amicable. His nephew Jacob (Clark Duke) lives in his basement, where he plays Second Life in lieu of having a life of his own. Lou (Rob Corddry) is the most miserable of all - and potentially suicidal, which is why his friends decide that it's time for a trip down Memory Lane.
They book a weekend in the ski resort where they cavorted as youths back in the '80s. The place is now a rundown dump with a malfunctioning (or is it?) hot tub that (I'll spare you the scientific details) transports them back to their glory days in the '80s, when the mountains were white with equal parts snow and cocaine and everybody sported brightly colored Spandex and really bad haircuts. Nick, Lou and Adam have fond (if vague) memories of fun and debauchery, and of the girls that got away.
In the interest of full disclosure, I must say that I loathed the 1980s and I feel not the slightest nostalgia for the Reagan years, which might unfavorably color my perceptions of Hot Tub Time Machine if it turned out that the '80s were even remotely worthy of revisiting in the movie. They are not. The fellas discover that their youthful indulgences were not actually that much fun, and are even worse to relive. Nick, Lou and Adam don't just go back in time; they are forced to relive a particularly eventful and distressing weekend of breakups, beatings and assorted indignities.
As the only member of the party who did not yet exist in the 1980s, Jacob cautions them to change nothing, lest the future be irrevocably altered such that he might not exist to spend his days in a dimly lit basement. Such are the rules of time travel, if you believe Stephen Hawking. I say, if you can't change the past, why bother visiting it? (For the record, Hawking doesn't actually say that you shouldn't change the past while traveling in time; he says that quantum effects will always conspire to prevent time travel. Quantum effects are like time cops: ruining everybody's fun, but making the universe safe for historians.)
But lo and behold, the guys realize that, as miserable as they are now (or whenever they are), they were pretty miserable back then, too. Wallowing in misery and self-pity is a skill that they've been perfecting for decades. It's pretty obvious that they're in for some old-school enlightenment, and male bonding will occur if they survive the sex, the drugs, the rock 'n' roll and the bullies. Hot Tub Time Machine doesn't let them off the hook; they are the architects of their own unhappiness, and if their trek through time teaches them anything, it's that.
Despite all the nostalgia on display and the overworked crassness, the movie is not, ultimately, nostalgic about either the '80s or misspent youth. I can get behind that. Remember Back to the Future? This movie does. Crispin Glover (a/k/a Marty McFly's father George) shows up in Hot Tub Time Machine as a belligerent one-armed bellhop. He shows up again in the past as a cheerful, helpful, two-armed bellhop. What happened to his arm, and his temperament, makes for one of the better running gags in the movie. Chevy Chase turns up too, and so does that guy (William Zabka) who played the bully in Karate Kid and a bunch of other '80s movies with bullies. And of course, Cusack is himself a walking, talking allusion to the movies of the 1980s (Say Anything, Better off Dead).
Ready to revisit Reagan-style redbaiting? Hot Tub Time Machine has got you covered. If you miss the homophobic, misogynistic sex comedies of the '80s...well, Hot Tub Time Machine has got something for you too. The movie is totally loaded with '80s pop-culture references, visual homages and stolen snippets of dialogue; but it also aims to be crude, rude and goofy. Like, totally. Director Steve Pink and the film's three screenwriters (Josh Heald, Sean Anders and John Morris) cram every square inch of the movie with Jheri curl, legwarmers, magic mushrooms, MTV-when-it-still-had-music (now I'm showing my age) and everything else that might send one's hippocampus skidding helplessly back to the dreaded era of Flock of Seagulls.
It's overload and overkill: an absurd, slapstick farrago of everything that was sad and ridiculous and mockable and laughably horrible about the '80s (which is a lot) and then some. For all that, Hot Tub Time Machine as experienced is not as much fun as one might think - which is a kind of meta-unfunness that mirrors the letdown of traveling to your past and discovering that it was less great than it looked from the distance of time. Is that good? It's kind of a bummer, actually.