"Guilty pleasure" is pushing it, but you might develop a certain guilty appreciation for the way this slab of breezeblock Brit-schlock goes about its ludicrously contrived business.
West End stage star Sheridan Smith is Becky, one of the top-floor occupants of the ironically named housing block Serenity House who, for reasons unclear, steadfastly refuse to move when everyone else has left.
You'd have thought the less obnoxious ones (Becky, the stoical older couple, the parents with the nerdy teenager, the lonely alcoholic) would jump at the chance to be rehoused somewhere potentially less grim.
But no, instead they choose to live alongside a shriekingly abusive single mother, a constantly bickering couple and a pair of doped-up wasters. All this while paying protection money to the biggest scumbag of the lot: Kurtis the drug-dealing Northerner (a brilliantly repulsive Jack O'Connell).
Anyway, one Saturday morning Becky is just getting to know the bloke she just woke up with when... well, let's just say if it wasn't his first one-night stand, it was definitely his last.
In one chaotic minute, it becomes clear that the block is under attack from a shooter who, given clearance by the IOC, would easily pass Michael Phelps' gold medal tally in a single Olympics.
Able to hit anything that moves in any of eight distant flats in a split second, the gunman soon has the survivors of his opening salvo cowering in the communal corridor.
What's more, once everyone stops arguing (the phrase "pull your head in" never seemed more appropriate) and starts to think about how they might escape, they find their assailant has not only cut all communications but left more nasty surprises on the inside.
"He's thought of every last detail" someone blubbers. Actually he hasn't. But Cockneys Vs Zombies writer James Moran is happy to bite the bullet of implausibility to give the killer every opportunity to execute his plans. Or plan his executions. Whatever.
But far from ruining the suspense, putting everything in his favour gives first-time co-directors James Nunn and Ronnie Thompson the freedom to have you gnawing your fingernails and ducking for cover whenever they like.
Stemming from the fatal beating of a teenager a few months earlier, it all turns out to be qan extremely harsh lesson in morality.
Speaking of extreme, it also features the most dramatic musical accompaniment to a microwaved spaghetti bolognese you're likely to hear. Ever.