What Coscarelli's achieved doesn't feel like an adaptation. It feels more like he seems he skimmed the source material, burned it, and then assembled a vague recollection on film after three days of untold indulgences.
"John Dies at the End" thinks it's "Buffy the Vampire Slayer" for dudes. But in its randomness, its vulgarity and its level of humor, it's more like the collected writings on the walls of a roadside men's room.
The "wackiness" (scare quotes included) is mostly ceaseless and tiresome, from the ravenous zombie neo-Nazi that leads things off to the Galaxy Quest rejects that figure in the movie's annoyingly anticlimactic finale.
John Dies at the End is joyously heterodox in its method, an everything-but-the-kitchen-sink mélange of sci-fi, black comedy, and action, with disquieting body-horror sight gags that at times recall David Cronenberg's Naked Lunch.
It's one of those films that might as well be announced with the words "cult classic" emblazoned on the marquee. It's an interesting failure that's almost worth seeing for that reason alone. Kind of. Not really.