“Hell Fest” falls on the “Why’d they even bother releasing this one?” end of the horror film spectrum.

Then you look around at the late Thursday preview audience and see a theater half-full for a movie that was so crappy it wasn’t previewed for critics, that arrives with so little marketing only the horror faithful know about it and will show up. For a day or two, anyway.

It’s a about a spree killer who shows up at a “Halloween Horror Nights/Howl-o-Scream/Haunted House” traveling expo, an impressively staffed and elaborately staged immersive horror experience.

The last thing you’d expect in a place with a Zombie Maze, Deformed School, Deadlands and other hellish hands-on frights is an actual nut with a knife stalking and killing people.

He did it a couple of years ago in a distant town, which we see in the opening credits. How he’s out to create more dead teenagers in this deathly dull “dead teenager movie.”

Three couples — Brooke and  Asher (Reign Edwards and Matt Mercurio), Taylor and Quinn (Bex Taylor-Klaus, Miss Tries Too Hard,and Christian James) and first-date crushes Nat and Gavin (Amy Forsyth and Roby Attal) get VIP passes for “Hell Fest.”

It’s a vast set-up (entirely too big to be a traveling troupe), and they’re not alone. Thousands have shown up. So has one guy in a hoodie. He brought his own mask, and he knows where to cadge a knife.

The stalk is on, the “What is WITH this guy?” questions, the taunting and then the one-by-one killings of characters so colorless describing them is pointless.

Horror-phobe Nat witnesses the first murder, and doesn’t believe it’s real. “Just DO it,” she says, getting into the spirit of things. “We came here to be SCARED.”

The killings aren’t particularly gripping, there’s little suspense in the earliest ones and the menace is pretty watered down for much of the movie.

There are two pretty tight sequences though — one involves a guillotine and an MC played by horror legend Tony Todd (“Candyman”). The other doesn’t. Don’t bother calling the cops, either.

“You came here to be scared. I can’t arrest people for doing their job.”

Aside from that, we have to get our jollies out of the detail in the various rooms (the grope-a-torium is a favorite). What must admission the admission price be, with all these buildings, all those employees and all that neon and technology?

MPAA Rating:R for horror violence, and language including some sexual references

Cast: Bex Taylor-Klaus, Reign Edwards, Amy Forsyth, Tony Todd

Credits:Directed by Gregory Plotkin, script by Seth M. Sherwood and Blair Butler. A CBS/Lionsgate release.

Running time: 1:27