The acoustics of the room are being pulverised by the hoots and squeals of hundreds of horror boffins and B-movie thrill seekers. We are watching Drew Goddard’s Cabin the Woods in a packed house — at Melbourne’s grandiose Astor Theatre, no less, where its 1150 seats rarely accommodate such a monster crowd — and it’s quite the experience, a cinephile couch potato’s version of going to the World Cup, donning a beer hat and roaring for the so-and-sos to beat the-so-and-sos.

Before the screening kicks off, the line to the candy bar extends what appears to be a good quarter mile. Enter stage left: a chirpy man wielding an open can of Sprite gets his weekly exercise by walking up and down it; if he isn’t employed here he’s being courageously inappropriate. The soft drink sipper is reassuring customers that the film will not start until each and every one of us are seated, a pleasing point of difference to the 15-year-old punks at the multiplexes who don’t give a toss whether the film starts, finishes or gets dropped in a bucket of hot butter.

The Astor’s legendary cat Marzipan, an institute unto herself (himself? hard to tell with felines) sits on an armchair watching the proceedings. If Marz is surprised that the theatre — currently in the thick of a campaign to save its glorious art deco edifice from becoming a gymnasium for acne-studded private school kids to give each other wedgies — has returned to the bustling busyness of its hey-day, albeit temporarily, she’s keeping it all inside.

This is the film, co-written and produced by sci-fi geek guru Joss “Buffy” Whedon, that came perilously close to falling into an open grave of direct-to-DVD ignominy, which would have been a humiliating death for such a fine product.

Cabin in the Woods is currently playing on a triumphant, erm, five or so screens across the country. Its distributor decided they couldn’t fleece enough money from audiences who, on this particular night, seemed almost literally gagging to cough up their hard-earned. It was a decision Astor management would hardly be disappointed with. The film gave the 80-something year old venue a much needed shot in the arm, a reminder the ol’ girl still has wind in her sails and it’s blowing out the right valve.

You may have noticed by now, this isn’t a review. Given this film is littered with twists and post-mod reflexes, layers of depth and deceit, the task of crafting a critique is perilous, the Whedon fan boys and gals ready to turn their flame throwers onto any hack insinuating the vaguest of spoiler.

While it’s not fair to whine about a reviewer who mentions a plot turn that transpires five or so minutes into a film, there is still a tendency — and there damn well should be — for critics to avoid concealing the gloriously grim gems it holds, even if some of them are exposed early in the game.

So, here’s what to expect. Thick globs of icky violence. Lots of occasions to whoop and squeal. Part Cabin Fever, part Night of the Living Dead with a splash of The Truman Show and Monsters Inc, linked to a thousand years’ worth of nightmares and grisly folk stories.