Existence: The Outer Reach is a real-time strategy game that immerses players in a vast galaxy where they command an expanding empire. Players can colonize planets by constructing bases and gathering resources to fortify their forces. The game features intense battles against enemy colonies utilizing mechs and native wildlife, while also allowing players to engage in space combat with their fleets.

Exploration is a key component, as players venture through the galaxy to uncover new planets, each with unique wildlife that can be trained for combat. Additionally, players can monopolize rare minerals necessary for crafting powerful weapons capable of annihilating entire planets, adding a layer of strategy to gameplay that emphasizes resource management and tactical warfare.