The metaphysical horror comedy novel John Dies at the End is a gonzo mash-up of Stephen King and William Burroughs that’s overflowing with creativity and gleeful weirdness. For his adaptation, Don Coscarelli (Phantasm, Bubba Ho-Tep) manages to cram as much of the novel’s key plot points and batshit insanity into 90 minutes as possible. The result is a relentless blast of humor and gore that’s destined for cult classic status, but not without its share of hiccups. The good far outweighs the bad though, and it’s safe to say that John is going to leave fans rabid for more adventures with inexplicable mind-altering drugs and inter-dimensional leech creatures.

The film’s brief prologue sets the tone for the playfulness, philosophical excursions, and horror comedy that follows. The vignette delivers a macabre riddle about killing a man two times with the same axe. It might be my favorite part of the movie. Then we’re introduced to David Wong (Chase Williamson), our protagonist and narrator, who is sitting in a dark Chinese restaurant, telling his unbelievable tale to a reporter (Paul Giamatti). The narrative frequently jumps back and forth through time and it could be easy to lose track of when the events are taking place. David’s story is long and twisting, but the bulk of it involves his best friend John (Rob Mayes) and their search for the origin and source of a powerful drug known as “soy sauce.” The sauce heightens perception and unlocks gateways in your mind. It’s like a telescope for your third eye!

At a party one night, John is given soy sauce by a mysterious Jamaican. Earlier, this same Jamaican read David’s mind and told him what he dreamed of the night before. David brushes the encounter off, but early the next morning he gets a phone call from a delirious John and after he swings by to take John to the ER, the two are picked up by the cops for the brutal murder of the Jamaican and several of the other party-goers. David is able to escape custody from a phone call by John, who continues to call him several times despite the fact that he might be dead.

From there the plot continues its barrage of supernatural weirdness and creature set-pieces – teetering on the brink of near-incoherence. We meet characters like the one-handed Amy, her dog Bark Lee, and a Vegas-style mystic named Albert Marconi (Clancy Brown – KURGAN!). They aid David and John as they pass through different dimensions in an attempt to find the root of the soy sauce and prevent an other-worldy invasion. These supporting characters, especially Marconi, feel clumsily placed in the film. There’s a scene in which Marconi explains to David and John how to cross to the other dimension that’s incredibly awkward. And Amy, who has a much larger role in the book, falls flat in the film as David’s love interest. Giamatti, who also helped produce the film, is fantastic as always.

At times, the pacing and editing feel just as awkward as the supporting characters. The confrontation with the other dimension’s supreme being is terribly anticlimactic and fizzles out right when you’d expect an attempt at suspense. There’s no time to celebrate before it’s a quick cut to another weird set-piece. It’s frustrating because there’s so much to enjoy in John, but Don doesn’t give us any time to soak it in. Individual scenes act well on their own, but as a whole it’s kind of a narrative shamble.

Every review I’ve read of John has panned its special effects, calling them “laughable” and comparable to SyFy Channel originals. I can see why, but I think it’s completely unfair to do so. This isn’t a big budget film – having seamless CGI wasn’t possible for Don and his crew. But they do make the best of what funds they have and we should all applaud them for being brave enough to go practical on many of the creatures. The day you’re too cool to enjoy a giant meat man with sausage fingers is the day you should give up.

For all of its faults, John stands as an utterly ballsy breath of fresh air. Zealous fans of the book are going to salivate over this film and use it as a friendship litmus test. Newcomers to Wong’s wacky world might be left with their head spinning, but wanting more. With a second novel, This Book Is Full of Spiders, set for this October, here’s hoping Don gets to revisit the series.

John Dies at the End just played the Florida Film Festival and Boston Underground Film Fest. No date has been set for a wide release.