Ancestors: The Humankind Odyssey is a single-player survival game played from a third-person view and set in an open world. Players control a member of a hominid clan and manage its needs by eating, drinking, and sleeping while facing predators and other dangers in the wild. Exploring new places and being hunted can trigger a state of fear, which is offset by rewarding actions such as crafting tools and making discoveries. As the clan learns and grows, players unlock new skills through a neural development system and can switch between clan members, passing acquired abilities to future generations. The game has no structured narrative campaign and instead lets players shape their own experience.

Set in the jungles of prehistoric Africa around ten million years ago, the game places the player in control of a clan of hominins, early members of the evolutionary line leading to modern humans. The world is an open, dangerous wilderness filled with predators and natural hazards, where every foraging trip, climb, and encounter carries risk. The player's goal is to keep the clan alive and guide it as it slowly grows, learns, and evolves. By exploring, making discoveries, developing new skills, and raising new generations, the clan gradually advances across a vast span of time toward becoming something new.