This Canadian slasher is the one with the killer in the miner’s gear, an indelible image from the early 1980s. It’s not a film that strays too far from the already established slasher pattern and is probably all the better for it. George Mihalka directs at a pleasingly brisk pace and with some atmosphere, particularly the scenes set in the mines.

The trends at the time were for slashers to celebrate in their own grisly way some sort of beloved holiday or event (Black Christmas (1974), Halloween (1979), Friday the 13th (1980), Prom Night (1980), You Better Watch Out (1980), New Year’s Evil (1980) et al) and to frequently feature events playing out in the present that are a direct result of a tragedy from the past ( Halloween, Friday the 13th, The Burning (1981) et al) and My Bloody Valentine certainly wasn’t looking to buck either of them. In the weird opening, set on 14 February, a scantily clad woman gets it on with a man in a gas mask in the mine (who is she? What’s she doing there? What niche sexual fantasy is this playing to?) getting the film off to a striking start. In the small down at heel mining town of Valentine Bluffs, the residents have refused to allow Valentine’s Day celebrations following a catastrophic mining accident that left several miners dead.

Sole survivor Harry Warden (Peter Cowper) resorted to cannibalism and went insane, returning to the town the following year to murder two supervisors who abandoned their men to their fate and warn that he’ll return again if the town’s Valentine’s Day Dance is ever allowed to go ahead again. Twenty years later, confident that Warden is long gone, Mayor Hanniger (Larry Reynolds) relents and agrees to allow the town’s younger residents to organise a dance. Hanniger and the police chief Jake Newby (Don Francks) receive what seems at first to be a box of Valentine chocolates which turns out to contain a human heart – Warden is back and soon a series of brutal murders occur, severed hearts being left around the town in similar chocolate boxes.

My Bloody Valentine suffers all the ills of the early 80s slasher – the acting is sometimes a bit shaky, the young would-be victims are almost universally unlikable buffoons, the plot is frequently nonsensical – but Mihalka keeps things moving at such a pace that it scarcely matters. And the alarming appearance of the killer, gas masked, sporting a utilitarian boiler suit and armed with a pickaxe, is certainly arresting enough to distract you away from plot’s many contrivances. The idea of a vengeful man thought to be dead delivering severed hearts to those who crossed him on Valentine’s Day, is not dissimilar to the Poetic Justice story in the Amicus anthology film Tales from the Crypt (1972).

And perhaps most importantly, it delivers on the gore. Or at least it does in its more or less “uncut” form. The film was famously butchered for its US release (and consequently almost everywhere else), the Motion Picture Association of America demanding numerous cuts in order to obtain an ‘R’-rating. Fans, having seen spectacularly grisly stills printed in Fangoria, were understandably dismayed when they saw what looked at the time to be quite an anaemic slasher. Mihalka has claimed that distributors Paramount (who were already facing some pushback after releasing Friday the 13th a year earlier) caved in to the MPAA as they were afraid that the film would suffer adverse publicity in the wake of the murder of John Lennon who had been shot by Mark David Chapman two months before the film was due to be released.

A partially restored version was released on disc in 2009, with three minutes of previously cut footage being reinstated. It’s still not entirely clear if that’s all of the missing footage as rumours have persisted that up to nine minutes were originally cut. For the moment though, this is all we’ve got, and the grisly effects designed by Thomas R. Burman, Ken Diaz and Tom Hoerber certainly add something a bit extra to the proceedings. The murders are certainly inventive – one victim is turned into a grotesque water feature in a dank basement, a woman is scalded in a clothes dryer at the town laundry, a woman (Helene Udy) is impaled on a shower head (where would a slasher be without a shower scene?), a head is shoved into a pot of boiling water and various mining tools – that pickaxe, a power drill, a nail gun – are pressed into gruesome service.

The silly ending sets up a sequel that Paramount declined to finance (they were disappointed that it didn’t make as much money for them as Friday the 13th, though it still did remarkably well at the box office), though such was the enduring popularity of the film that it was remade, in 3D no less, in 2009. As with so many slasher films, it’s best not to worry too much about the plot and its often-tortured machinations – just go with the flow, soak up the not inconsiderable atmosphere and enjoy its often tongue in cheek take on the genre. It remains one of the better slashers from the 1980s.