“Marcel the Shell with Shoes On” is a charming little stop-motion animated project built on an Internet/Youtube sensation from long ago. Well, pre-Pandemic anyway.

Dreamed up by Jenny Slate, then freshly-dropped from “Saturday Night Live” for dropping a live f-bomb, and her then-husband Dean Fleischer-Camp, it’s about a one-eyed, talking hermit crab shell with pink sneakers.

The humor is built around mousy-voiced Marcel (Slate, who also does voices of “Bob’s Burgers” and many others) observed coping, adapting and DIYing his way through the human-scaled world, drolly commenting on what he’s experiencing and what he’s observing, always with a child’s understanding.

“Marcel the Shell” starts with the sight gags — a tiny shell showing us his diet, interacting with (stop-motion-animated) bugs and a live Jack Russell terrier, throwing up on a car ride and, once he’s gotten Internet famous, bouncing on a MacBook keyboard, writing or web searching his Youtube videos, marveling at how many people watch this ongoing “documentary” about him.

He interacts with the human whose house this now is, Dean (Fleischer-Camp), who talked Marcel into being interviewed for his documentary. Marcel, sometimes reluctantly, demonstrates ways he gets around, gets things done and improvises transport (he cuts a hole in a tennis ball and rolls around), uses wire-tops from champagne corks to make tables and chairs, etc, and turns a sewing machine into a gadget that tugs on twine that shakes a tree out the window so that he and his grandma can harvest apricots.

“I like myself,” he opines, “and I have a lot of other great qualities as well.”

An aproned woman periodically comes into the house where he lives — “She’s a harbinger of the vacuum.”

His beloved Grandma Connie (Isabella Rossellini) is another shell with shoes, and a more reluctant participant in interviews for the film. She requires some explaining, Marcel figures.

“She’s not really from here. She’s from the garage. That’s why she has the accent.“

That’s the other source of giggles, Marcel’s deadpan humor. A teeny, tiny living shell has to flee things like vacuums and a friendly, curious canine.

“I actually like the concept of having a dog.”

The film tells the story of Marcel wondering where his and Connie’s family and “community” went, and shows us flashbacks of another couple arguing, splitting up, and in the noise and confusion of that, hiding shells — friends and family — must have been whisked away in the move.

That takes this story into something deeper, or at least bittersweet. Marcel is lonely, and he wants his grandma to have that community around her as well. Helped by Dean, he starts the process of searching — via Marcel’s comically childish (and inadequate) clues and Google search ideas.

“Marcel the Shell” takes on an undertone of childhood longing, loss and grief as Dean’s posted videos make The Shell with Shoes famous, but brings Marcel and his Grandma the stress of overzealous fans who find Marcel’s house, while getting them no closer to finding their community.

Maybe Granny’s favorite TV show and TV interviewer, Lesley Stahl, can help.

The back-story to this project — which took years to complete — is that Slate and Fleischer-Camp split up themselves, and yet agreed to carry on with it. That split gives a poignant, wistful undertone to “Marcel” if you know about it coming in.

There’s also the unmistakable sense that this years-in-in-the-making stop-motion tale, built on ideas, jokes, and Internet novelty from a dozen years ago, kind of missed its moment. Twee can have a short shelf life, and once we’ve gotten the Youtube-length-joke the picture loses some of the edge that makes it interesting.

But while “Marcel the Shell with Shoes” might have lost its cutesy, two-person production DIY cachet, he finishes the journey to the big screen with his charm and Slate’s wit intact. What he goes through can be laugh-out-loud weird, and surprisingly touching. And if this film is Marcel’s teeny, tiny curtain call as a cultural phenomenon, it’s a perfectly adorable one.

Rating: PG, some suggestive elements.

Cast: The voices of Jenny Slate and Isabella Rossellini, with Dean Fleischer-Camp, Rosa Salazar, Thomas Camp and Lesley Stahl.

Credits: Directed by Dean Fleischer-Camp, scripted by Dean Fleischer-Camp, Jenny Slate and Nick Paley. An A24 release.

Running time: 1:28