Under a Rock is a procedural open-world survival craft game designed for 1-10 players, set in a unique environment where oversized wildlife, Neanderthals, and real curses add to the challenges. Players assume the role of an early nineteenth-century explorer stranded in a hidden world with a distinct evolutionary path. The game features diverse settings, including dark caves, underwater landscapes, and a vast surface world, each presenting unique obstacles and resources to discover.

The gameplay emphasizes exploration and creativity, allowing players to craft, build, harvest, farm, fish, and engage in combat. With a procedurally generated world, every playthrough offers a fresh experience, whether players choose a peaceful coastal lifestyle or confront the native inhabitants. The game encourages players to adapt to their surroundings and make strategic choices as they navigate the dangers of this primitive realm.