If you discovered a tiny sentient talking shell while staying at an Airbnb, your first inclination would probably not be to befriend it and make a documentary about it. Yet it’s easy to accept the inherent goodness of the title character in Marcel the Shell With Shoes On, and to be drawn into his unlikely world. That’s the power of the movie from director, co-writer and star Dean Fleischer Camp, who takes a character created for cute online videos and builds a quietly profound story around him.

Fleischer Camp created Marcel with Jenny Slate, who also provides Marcel’s voice, in an engaging performance that mixes childlike wonder with seasoned wisdom. That balance is key to the movie’s brilliance, as it draws the audience in with a goofy-looking character and the inherent humor of such a tiny creature attempting to navigate a world that’s so much bigger than he is. There’s a melancholy undercurrent to all of Marcel the Shell’s humor, as Marcel’s ingenuity and optimism come from the necessity of facing life without the family he’s seemingly lost forever.

“It’s pretty much common knowledge that it takes at least 20 shells to have a community,” Marcel says to Dean (playing a version of himself) at the opening of the movie, establishing both the matter-of-fact approach to the character’s fantastical world and the sense of wistfulness and loss that Marcel carries with him. Marcel’s community was torn from him in a comical yet tragic moment, carelessly tossed into a suitcase by half of the feuding human couple that owned the house containing the shell society.

Marcel relates this story to Dean in one of many confessional interviews, as the indie filmmaker puts together a documentary about his unexpected roommate. After the couple’s break-up, only Marcel and his grandmother, Nana Connie (Isabella Rossellini), were left behind, and Marcel has no idea how to locate the rest of his family and friends. Marcel and Nana Connie make do on their own, coming up with elaborate solutions to find food, get around the house, and avoid danger.

Marcel takes it all in stride, but meeting Dean opens up a whole new world for him, especially once Dean’s videos of Marcel go viral online, and he amasses a following in the same way that the original Marcel shorts did in reality. “There’s so much nothing,” Marcel says of what he finds on the internet, but as with everything in Marcel the Shell, Fleischer Camp and Slate focus on the positive. Marcel eventually experiences a bit of the dark side of online fame, when influencers find the house and loiter outside, but almost all of the response he gets is supportive, and it brings him to the attention of his idol, 60 Minutes reporter Lesley Stahl, who appears as herself.

There’s a purity to both Marcel and Nana Connie that’s reflected in their enthusiasm for 60 Minutes, an old-fashioned TV newsmagazine that’s the polar opposite of online videos. The relationship between grandson and grandmother is generous and sweet, and as Nana Connie’s health declines, Marcel prioritizes her comfort over his own. Rossellini brings remarkable emotional depth to her voice performance, playing Nana Connie with the same care and consideration she’d bring to a live-action human character. Her gentle encouragement of Marcel to live his own life even as hers is coming to a close will be recognizable to anyone who’s had a close relationship with a grandparent.

That warmth and honesty between characters who look like discarded children’s art projects is what makes Marcel the Shell so sneakily affecting. Marcel expresses amazement at simple things like breezes and raspberries, but he can also quickly pinpoint Dean’s own neuroses related to a recent marital separation. Nana Connie seems like a doddering old woman at times, but she has the kind of insight that only comes from living a life full of both deep sorrow and great joy. “She didn’t get sanded down by life,” Marcel says when paying tribute to his grandmother.

Marcel the Shell was nominated for an Oscar for Best Animated Feature, and the stop-motion animation of Marcel, Nana Connie and their miniature world is gorgeous. What gives it greater resonance, though, is its interaction with the concrete live-action surroundings, and with humans like Dean, Lesley Stahl, and the bickering homeowners (Rosa Salazar and Thomas Mann).

Marcel teaches both those people and the audience about appreciating everyday pleasures and relationships, but he’s not just a tool for the self-improvement of others. He’s a fully realized person (or shell) whose hopes and dreams continue beyond Dean’s documentary about him. Witnessing that heartfelt complexity provides the kind of genuine life-affirming experience that very few movies can achieve.

Marcel the Shell With Shoes On is now streaming on Netflix.