Horror anthologies are notoriously spotty, and “The ABCs of Death,” a brainchild of Alamo Drafthouse CEO Tim League and producer Ant Timpson, proves that it’s impossible to round up 26 voices in a genre as subjective as horror and not have a few segments stand out and a few fall short. Even though the film is often wildly entertaining, especially as it enters the home stretch, it is often exhausting to take in and makes for an inconsistent but one-of-a-kind experience.

The concept is simple. 26 directors each handle a different letter of the alphabet and a corresponding horrible demise. From the bluntly funny “A is for Apocalypse” to the utterly ridiculous “Z is for Zetsumetsu”, the Japanese word for extinction, “The ABCs of Death” swings from subtle to over-the-top, grossly silly to genuinely disturbing, and fiendishly clever to thuddingly obvious.

“The ABCs of Death” unfolds in alphabetical order and the film’s first half is troublingly spotty. Some segments, like a samurai-centric goof or the visually striking “O is for Orgasm” are total nonsense strung together by the thinnest of concepts. Others are simply bizarre, like “F is for Fart,” which is so preposterously juvenile and undeniably funny that it must take place inside a sixth grader’s mind. Acclaimed horror director Ti West chimes in with another short that’s easily the worst of the film — a cheap-looking joke in search of a punch line.

Other segments impress, like the elegant and beautifully shot “D is for Dogfight,” or a hilariously fetishistic real-life rendition of a Tex Avery cartoon whose means of demise are better left unspoiled. But even the best shorts still suffer in the film’s marathon of carnage. By the time you’re past the first few letters of the alphabet, “The ABCs of Death” starts to drag, and the film really works best watched either in a packed theater, with an enthusiastic, and preferably drunk, crowd cheering on each demise.

Things pick up momentum as “The ABCs of Death” starts to work its way to Z, and Adam Wingard, director of “You’re Next,” gives the film its best segment, the hilariously meta “Q is for Quack.” The film barrels through the alphabet from there, nailing the mix of socially purposeful bloodshed with dark humor and creative concepts.

“T is for Toilet” won a contest to be included in the film, and the short’s claymation presentation makes for some of the film’s silliest gore and sharpest jokes. From there, up-and-coming horror directors Ben Wheatley and Jason Eisener contribute darkly humorous, recognizably specific shorts, and even the sci-fi mash-up “V is for Vagitus” packs some great ideas in with its massive body count.

“The ABCs of Death” is far from a great film, but it never fails to entertain, even as it becomes a slog to get through. The 123-minute runtime is nearly insurmountable for a horror film but necessary to this film’s concept, making “The ABCs of Death” a film worth seeking out as something to be experienced, not enjoyed. Despite its inconsistency, “The ABCs of Death” is an ambitious, worthwhile sugar rush of a film whose entertainment value hinges entirely on the viewer’s ability to hold off the inevitable crash back to Earth.