Stray is an action game with puzzle elements following a cat surviving in a neon-lit, decaying cybercity inspired by Kowloon Walled City. One day, the cat is separated from its family and tumbles down deep inside the underbelly of the city. Looking for a way back, it roams the environments and meets the droids left behind, inhabiting the world devoid of the humans who designed them. The game mixes different types of gameplay in a largely linear experience. The gameplay is varied, with sections involving linear corridors where the cat slowly explores and finds a route, or fast-paced areas where it must navigate through groups of Zurks, creatures that try to jump the cat. It's possible to die in these sections, so quick navigation is required combined with puzzle-solving. A Defluxor device becomes available later on, which can be used to destroy the Zurks using UV light.
Other sections offer more freedom, with a large hub environment where the cat can explore and solve puzzles. Locations can be explored in any direction, getting on rooftops or sneaking inside buildings through windows. The cat can also talk to characters through its B-12 flying drone companion, which provides hints and helps navigate the surroundings.
The gameplay is influenced by typical cat behaviour, with actions like meowing to attract attention, pushing down items off objects, hiding in cardboard boxes, or jumping on levers to activate them. Many of these interactions are optional, such as lying down to sleep or nuzzling up legs.