“Planètes” or “Dandelion’s Odyssey,’ a delightful dialogue-free animated tale of a group of adorable dandelion seeds, adrift in space and seeking a new home after Earth is obliterated by nuclear war, doesn’t initially sound like the most hopeful of stories.

But at a Cannes Film Festival that has been defined by the sense that the world is going to hell with haunting films that take on everything from the reverberations of abuse to the perils of postpartum depression and the devastation of losing those you love, Momoko Seto’s small, often silly, little gem of a film still stands apart. It’s more than a bit scrappy — the animation can be somewhat crude at times — but it wins you over with just enough earned charm as it sets forth on a small-scale, interplanetary adventure.

In “Planètes,” a nuclear bombardment swallows the world in fire and sends the humble dandelion seeds floating through space.