The Cabin in the Woods is less a horror film and more of a puzzle box that exhumes and examines the gratification we derive from gruesome entertainment.

In other words: If you thought the film’s sole goal was gutting college kids in the sticks, stop reading and come back later. Even saying the movie is not as it seems constitutes a spoiler (albeit one far less specific than those in omnipresent trailers and TV spots). But that’s part of what the movie chews over.

So run along — because you should if you’re a horror aficionado — and we’ll see you later.

Now that you’re back (or just throwing caution to the wind), here’s some more detail, albeit with as few spoilers as possible.

So entangled are Cabin’s surprises and subtext that it’s a movie about which you want to say everything and nothing. Leave it to co-writer Joss Whedon — exalted leader of the pop-culture geek chorus (Buffy the Vampire Slayer, Angel, Firefly) — to extract symbolism from a bong that collapses into a coffee mug. Like that apparatus, which comes in handy for the movie’s stoner, Cabin prides itself on misdirection.

It’s a fan dance for fanboys that gives up the goods of gore and T&A while tweaking why we like to see, or create, such things. Cabin is smart to tackle many topics under that umbrella, and it crams in a lot that’s good, but never quite great.

Clever and comical enough, Cabin is also cold and clinical — a purely technical exercise that’s more thesis statement than loosey-goosey good time. Compare what unfolds here to two multi-episode South Parks covering similar territory several seasons ago, and Cabin remains dry and detached even as guts and goop erupt.

It also touches on the idea that filmmakers, to feel creatively fulfilled, sometimes introduce ideas that alienate the very audience they seek to attract. And all that we, as that audience, give in return is either a groan or a grin when it’s done — a thumb up or down to judge a horror film’s fate like a bloodthirsty emperor.

Filmed three years ago, Cabin tweaks the bigger-better-faster-more mentality that now certainly hangs like a cloud over Whedon’s The Avengers — which he couldn’t have possibly dreamed he’d get to write and direct way back in 2009.

Cabin also flirts with criticizing modern horror in a sharp, pointed way until … well, it just abandons excitement or anger about much of anything. (The lone exception is a well-executed gag about how repetitive and routine the J-horror genre has become.) Telling are Nine Inch Nails lyrics in the end credits song: “Gave up trying to figure it out, but my head got lost along the way.”

Alongside co-writer / director Drew Goddard (Cloverfield), Whedon has essentially presented a proficient, but strangely passionless, plea that’s maybe-sorta-kinda on behalf of preserving originality in horror. Or maybe not.

The plot, at its most basic description: Five college coeds — a jock (Chris Hemsworth), a party girl (Anna Hutchison), a stoner (Fran Kranz), a sensitive scholar (Jesse Williams) and a nubile naif (Kristen Connolly) round up in an RV and head to a relative’s rural cabin for a weekend of sex, drugs and drinking. (Every performance is fine in its purposefully archetypal way, although, after his petulant Thor, Hemsworth continues to display skill at playing assholes.)

In the cabin’s creepy cellar, they discover a diary filled with accounts of brutal, Old Testament killing rituals and, in a hilarious bit, the phrase “husband’s bulge.” (Although it’s Whedon’s way to err on smarm over charm, Cabin draws quite a few belly laughs, especially from Kranz’s running commentary.)

Little do they know that, much like Ash and pals in the Evil Dead films, reciting a creepy Latin phrase invokes a resurrection of zombie rednecks who want to fillet them.

Meanwhile, we’re introduced to two middle-aged characters in an office, played by Bradley Whitford and Richard Jenkins. They’re two of the last actors we expect in a horror movie, but it’s not their first rodeo with oddball comedy, and their alternately bored and bawdy banter gives the film a kick.

Those paying attention will piece together just how these divergent narratives are intersecting rather early on. But, as mentioned earlier, the trailers and TV spots have done an even more unfortunate job of tipping the film’s hand.

And see, there’s another self-reflective wrinkle the movie creases into 90 minutes: In an age of increasing entertainment options, trailers give up the goods to get asses in seats. So while Cabin’s surprises would have been more sacred in an age before a surplus of information, its subtext is somehow strengthened by the (at least partial) knowledge that it’s headed somewhere different from the outset.

In the end, is Cabin much more than Whedon and Goddard flexing muscles in mental masturbation? Not really. But watching them pull it off is worth a couple of tickets to their gun show. After all, as one character says, it is a lot cooler with a Merman.