When we reflect on the golden age of the slasher genre, we typically remember the films that spawned a string of sequels. After all, Freddy, Jason or Michael Myers popped up at the multiplex pretty much every year, and so they had a lot of time to make an indelible impact on pop culture and become horror icons, even if the original film didn’t necessarily cement their legacy. But there are so many other excellent slasher flicks released during the 1980s that don’t receive the same recognition among general audiences simply because they did not birth a franchise, and one of the most noteworthy in that category is 1981’s Happy Birthday to Me. With another birthday-themed slasher movie, Happy Death Day, hitting theaters on Oct. 13, let’s take a look back at the other film to combine blood and guts with candles and frosting.

Happy Birthday to Me was released three years after John Carpenter changed horror forever. Following the smash success of Halloween, dozens of entries into this growing slasher genre flooded the marketplace, though some had more in common with the Italian Giallo genre than with anything Carpenter did. Over-saturation was quickly becoming an issue, as evidenced by the fact that Happy Birthday to Me wasn’t even the only birthday slasher movie to be released in 1981; Bloody Birthday came out the previous month. It also wasn’t the only slasher movie of the year to have a final girl named Ginny; Friday the 13th Part 2 beat it to the punch by two weeks.

There became two primary ways to stand out from the slasher crowd at this time: center the movie around a holiday or special occasion (Friday the 13th, Christmas Evil, New Year’s Evil, April Fool’s Day, Mother’s Day, My Bloody Valentine, etc), or market the film entirely around the kills, promising even wackier and gorier murders than the competition. Columbia Pictures did both with Happy Birthday to Me, the poster for which promises “six of the most bizarre murders you will ever see.” One of those bizarre murders was at the center of all of the advertising: a man being impaled by a shish kebab. “Sure,” the film said to the audience, “there may be seven other slasher films vying for your money this year, but do any of them feature death by shish kebab?” Studios were engaging in something of a kills arms race, with every movie attempting to one-up the over-the-top deaths of the previous one.

But as it turns out, Happy Birthday to Me isn’t all about the gore and exploitation. In fact, it was described as a “psychological mystery shocker” in the official press pack. The story is centered around a private high school, where an elite clique refers to itself as the “Top 10” and only seems to spend time with one another. Things get started right away with a girl named Bernadette being stalked by a killer on her way to meet her friends, and as usual, the audience gets some point-of-view shots from the perspective of the unseen antagonist. The first victim is refreshingly smart here, pretending to be dead and then running for her life, though she just ends up getting her throat slashed anyway.

With Bernadette disposed of, our main character becomes Ginny, a relatively new member of the Top 10 who we learn has a traumatic backstory that she can’t fully recollect. After an accident years earlier, she underwent an experimental medical procedure that involved her brain tissue being repaired, and in the present day, a psychiatrist encourages her to recall her repressed memories. As Ginny is grappling with enigmatic flashbacks to some incident that took place around her birthday, members of the Top 10 begin to go missing, being offed in increasingly ridiculous ways by a killer who always remains off screen. We’ll be talking spoilers from here on out, so now’s the time to turn away if you haven’t seen the film and want to discover the insanity of the rest of the plot for yourself.

What’s great about Happy Birthday to Me is that it’s virtually guaranteed that you will not figure out the twist ending, and the movie plays the audience like a fiddle until the closing moments. We’re instructed to try to guess who the killer is from the opening scene, which makes clear that it’s somebody that Bernadette personally knows. This indicates that we’re not dealing with some supernatural madman like Jason Voorhees and that there’s an actual, solvable mystery at the center of the story. Suspects abound, but for the first act, we think that the killer has to be Alfred. He’s clearly the strangest member of the group, and it just so happens that he’s really into taxidermy like only psychopaths are in horror movies. At one point, Alfred stares very angrily at Etienne, and in the next scene, Etienne is coincidentally murdered, so this seems like a pretty open and shut case.

It becomes so painfully obvious that Alfred must be the killer that we then begin to feel that this is a red herring and that the murderer has to be someone else, the most likely candidate being Ginny herself. There’s a lot of evidence pointing in her direction, though the movie keeps the hints subtle enough that we don’t feel like we’re intentionally being led down this path at first. As the film progresses and it becomes clearer and clearer that Ginny’s mysterious backstory is somehow connected to the murders, we watch smugly as we believe the movie wants us to suspect Alfred (and, later, Rudi) because we think that we’re impervious to its tricks and that we’re one step ahead of the mystery. In reality, we have not come anywhere close to predicting the actual ending, but once we settle into our Ginny theory, we stop guessing.

At a certain point, the movie appears to have stopped being a mystery and has fully revealed Ginny to be the killer, an interesting twist on the format. First, Ginny has a bloody confrontation with Rudi, and then she flat out kills Alfred with garden shears while wearing black gloves. We believe that we’ve now witnessed the equivalent of the Pamela Voorhees reveal in Friday the 13th, and now the last act will probably just be about Ginny struggling with the fact that she keeps killing people but can’t remember doing so. Soon, Ginny’s full backstory is revealed: she was in an accident after her mother threw a birthday party for her that no one went to, and so presumably Ginny is now unconsciously murdering everyone who didn’t attend that night; they all went to Ann’s party instead.

But then we get to the completely bonkers ending, and to describe it as a sharp turn would be an understatement. Ginny’s father returns home to find all of the murder victims seated around a birthday cake, and Ginny is acting like a psychopath. But there’s someone else seated at the table: the real Ginny. It’s revealed that Ginny is not actually killing people without remembering it; there are two totally different people here, one of whom seems to be Ginny’s twin sister. Except no, wait: the killer pulls off a ridiculously realistic mask Scooby-Doo style to reveal that it’s Ann, Ginny’s best friend, who has committed all these murders in order to frame Ginny. Oh, and they are are half-sisters, by the way; apparently, Ann is upset that her father had an affair with Ginny’s mother. All the times that we saw Ginny go crazy and kill someone, it was really Ann in disguise.

This is a twist that is in some ways frustrating, as it comes so hilariously out of left field that it feels like there was no real way to predict it. It also doesn’t make total sense. If Ann’s plan involved framing Ginny, and if her Ginny costume and impression were so darn good, why wear black gloves and remain silent during all of the killing scenes? Regardless, the ending is just so shocking and preposterous that one can’t help but admire the fact that the movie pulled one over on us and delivered such a goofy surprise. Apparently, this twist came late into production, and the final reveal was originally going to be that Ginny was the killer and was being possessed by the spirit of her deceased mother. So it’s unclear whether what feels like brilliant misdirection earlier in the movie is intentional or just a side effect of the film being structured around a different ending. Still, the effect on the audience is the same, even if it wasn’t part of a master plan.

Happy Birthday to Me is one of those movies that’s all about the ending, but how does the film hold up outside of that? All in all, it’s still a fairly enjoyable slasher until the last five minutes, and the kills are solid, though only three of them can really be considered “bizarre” as the poster promises. Those would be the shish kebab death, the motorcycle scarf death, and the movie’s best kill: the weight room death, in which the killer adds more and more weights to a barbell and eventually drops a weight right on the victim. (A key death in Final Destination 3 would later feel like the natural progression of this). We don’t end up seeing that much blood, though, and the other deaths are fairly unremarkable: three people have their throats slit, two people are stabbed, and one person is hit over the head with a fire poker. Weirdly, the most graphic moment in the movie is a realistic surgery scene that calls to mind Eyes Without a Face or, more recently, the opening of Saw IV. But those who watch the movie just to witness six bizarre deaths will probably be disappointed.

The film could also use some trimming. With a running time of 110 minutes, it’s one of the longest slasher films ever made, about 20 minutes longer than Halloween and Friday the 13^th. Some of that time is spent developing the characters and making sure the audience gets to know them, but some of it is spent on pointless scenes that go on for way longer than they need to, including a full two minutes watching a soccer game that doesn’t really lead to anything. It’s nice that the movie is concerned with fleshing out the teenagers and making them more than just stereotypes, but many of these scenes don’t exactly do that, and there’s a point where it just feels like the movie is wasting our time. There’s also a bit too much of the psychiatrist character, who mainly seems to exist to explain the concept of repressed memories, similar to the unnecessary psychiatrist explanation at the end of Psycho. Had Happy Birthday to Me been a lean 90-minute feature, it would be easier to recommend.

One aspect of the movie that it’s difficult to be disappointed with is the score, which is among the most effective of the slasher era. The main piano theme is haunting and memorable; it’s actually significantly superior to the Friday the 13^th theme and could probably have become as iconic as John Carpenter’s Halloween theme if only the movie itself were more widely viewed. Tragically, when the film was released on DVD in 2004, it had different music, but the original score was later restored and is thankfully present on the Shudder version. Outside of the score, the movie goes through the effort of ending on an original song, which adds lyrics to the main melody as song by Syreeta Wright. The whiplash of the insanely dark ending and the haunting final theme creates for one of the all-around greatest last 10 minutes of any horror movie ever, with the credits certainly being included.

All in all, Happy Birthday to Me has its flaws, with the most prominent issue being the length. Like Sleepaway Camp, it’s the ending that really makes it stand out, though it’s subjective whether the final twist is clever and unexpected or just dumb and unearned. But the original Friday the 13th is also a flawed movie with an almost unguessable twist ending, so why is it considered a classic while Happy Birthday to Me is only remembered by hardcore slasher fans? It’s probably just that one received nine sequels while the other received zero, as Happy Birthday to Me is roughly as good. For those seeking a slightly more obscure horror flick to watch this October that will take them to some weird places and leave them laughing in bewilderment, Happy Birthday to Me might just hit the spot, and it’s deserving of some respect for its contribution to the slasher canon.