If you were asked to make a courtroom case for Lupita Nyong’o’s ability to do literally anything, “Little Monsters” would be Exhibit A. (This is an actual thing that happens often in our judicial system, don’t bother looking it up.) Co-starring as a patient and cheerful kindergarten teacher whose class field trip is interrupted by an inconvenient zombie uprising, she sings, gets laughs, talks tough, wields a shovel and pitchfork, and expertly navigates a big monologue about Neil Diamond. She’s so good, in fact, that the pleasure of her performance makes “Little Monsters” worth seeing. But just barely.

The trouble, you see, is that it is a decidedly supporting role. The protagonist is David (Alexander England), a slacker in a life crisis; his longtime girlfriend has finally ended their toxic relationship, he’s out of work, and though he proudly continues to insist that he fronts a metal band, they broke up years ago. He’s crashing on his sister’s couch and quickly wearing out his welcome; he’s only along on the field trip because he desperately wants to sleep with his nephew’s teacher, Miss Caroline (Nyong’o).

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Soon enough, he finds himself having a perfectly miserable time at Pleasant Valley Farm (“Now with mini-golf!”), situated right next door to a U.S. Army training facility that, it seems, houses zombies. And then said zombies get out, old-school, Romero-style undead, plodding through the countryside, ready to feast on farm workers and little children. The chaperones board themselves up in the gift shop, along with an obnoxious kids’ show host (Josh Gad, well cast) who lets them all see the monster behind the mask.

So what we have here is a reasonably clever premise for a “Night of the Living Dead” update, but unfortunately, “Little Monsters” never pushes past that premise. Writer/director Abe Forsythe has about three comic notions (most notably, that it’s funny to say wildly inappropriate things around five-year-olds–that one gets a real workout) and he just keeps circulating them, spinning the picture’s wheels until its 90 or so minutes have passed.

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Forsythe also asks of his audience a considerable amount of patience for David, and it’s a big ask, because he’s a real shit. England does his best with the role, but it’s kind of hopeless, yet another sub-Apatow stoner schlub whom we’re intended to cheer for, as he inexplicably gains the affection of a beautiful, intelligent woman. It’s supposed to be a big payoff when, in the end, our hero has somehow musters up the energy to be a decent human being, but really, seriously, who cares? Gad similarly smashes up against the limitations of the writing; his one-joke character comes off as little more than Smoochy cosplay.

Which leaves us with Nyong’o, admirably game – but is this really the best role available to a recent Oscar winner? Nevertheless, she digs in, all smiles, on an unflinching mission to convince her charges that the attack of the undead is just a big, fun game (When they ask why she’s covered in blood after an ill-advised trip out of the gift shop, she responds, “I got caught in a jam fight!”). She’s great, and the biggest problem with “Little Monsters” is that she’s ultimately starry-eyed support to a lame dude. About halfway through, it became very clear to this viewer that they’d made a movie about the wrong character. I wonder how deep into the production the filmmakers were when they came to the same conclusion. [C]

Check out all our coverage from the 2019 Sundance Film Festival here.