Cabin Fever is about as scary as a third-grade play, but it is mean-spirited, nihilistic, cynical and, if you enjoy mean-spiritedness, nihilism and cynicism, very funny. If not, knock off two stars and watch 28 Days Later.

Doing that would be perfectly justifiable and, if you’re actually looking for something that is what it says it is, a perfect evening. Seeing as how this film’s fraudulent marketing as a fright-fest will no doubt lure in countless filmgoers, consider this a fair warning.

Sure, this story about five college students besieged by a flesh-eating virus in the woods is an all-you-can-watch buffet of blood, guts, drugs, booze, nudity and sex. At least it’s honest about being a lovingly retro offering to the ’70s horror shrine. But it’s all a huge sick joke, like Very Bad Things with a flesh-eating virus thrown into the mix.

Writer-director Eli Roth points a morbid finger at his morally reprehensible characters and, thankfully, tries to arrive at no smarter conclusion that these people will get exactly what they deserve. Watching their situation go from bad to worse is no great surprise, but it is kind of fun.

Credit for this goes to the actors, all of them smart enough to play selfish, smug and stupid before going off the psychological deep end without veering into parody. James DeBello is good as Bert, a human personification of Butt-head, and as the seemingly levelheaded Paul, Rider Strong makes like Kevin on The Wonder Years until he goes native and homicidal.

Of course, there are obligatory gags about the backwoods folks, some that work and some that don’t. The young child who likes to bite people and do karate moves would be good even without the mullet (the cheap-joke gift that keeps on giving). Giuseppe Andrews as a party-hungry deputy takes over each scene he’s in. But the punchline about a racist shopkeeper is not nearly as funny as Roth thinks it is and definitely not worth waiting through the whole movie to deliver.

Plus, his narrative can get distractingly lazy (where did this virus come from, again?) and visual references to Quentin Tarantino, Sam Raimi and his sometimes-mentor David Lynch aren’t precious, just pretentious. And after Donnie Darko and Sexy Beast, the whole hallucinatory man-in-a-bunny-suit thing just feels tired, although Roth claims he wrote it before that was cool.

As clumsy as Roth gets with Cabin Fever, there is enough to suggest he’ll be a so-so satirist if nothing else. This is a movie worth laughing at, even if it’s not the one people expect to see.