In the latest issue of Empire, John Cusack says of Hot Tub Time Machine, “I think if you get a great title for a movie, the rest will write itself.” One hopes he’s not being entirely serious. Unfortunately, the makers of HTTM seem happy enough to let the concept do most of the work.

Adam (Cusack), his old buddy Nick Webber and his nephew take their suicidal, alcoholic friend Lou back to the ski resort where they spent some of the highlights of their youth. Here, an accident with a hit tub turns it into a time machine which transports them back to 1986, obliging them to grapple with the risks of the Butterfly Effect and the temptation of changing their futures for the better.

So far, so good. But much of the comedy is puerile; lots of dick and blow job gags, with a ridiculously unconvincing bit of projectile vomiting near the start setting the tone. I like a good knob gag as much as the next man, but the regret the characters feels for their hopes and dreams – you know, the emotional core of the film – gets smothered under a steady flow of bodily fluids.

Cusack is good, of course, but deserves better. Chevy Chase has a peculiar cameo as a possibly magical/science-fictional hot tub repairman, which doesn’t really work. If going for an 80s icon, why not someone who was in Back to the Future (Crispin Glover has a part, after all)? Then again, Bill Murray would have been better, but frankly the film isn’t aiming for that kind of quality.

A couple of other good points: Lizzy Caplan is in it, though in a too-small part, and any film which includes Animotion’s Obsession on the soundtrack wins points from Uncle Frank. Though it also reminded me how much more I enjoyed Adventureland last year.

Still, if you like toilet humour and are old enough to have seen Back to the Future in the cinema, this is very much the film for you.