Baba Is You is a tile-based puzzle game. The player controls (usually) a cartoonish creature named Baba, and has to get Baba to a level goal. The levels also contain various other objects (walls, rocks, doors etc.) with differing properties. The rules governing the behavior of these objects are depicted within the levels as simple sentences. For example, "Rock is Push" indicates that rocks can be pushed, "Wall is Stop" indicates that walls are impassable, and "Baba is You" indicates that Baba is the controllable character.
However, in a twist, the words that make up these sentences are treated as physical objects in their own right, and can be pushed around to assemble new sentences and completely change the game rules. For instance, the player can disassemble the sentence "Wall is Stop" so that walls can be passed through freely, or assemble the sentence "Rock is You" to let him control the rocks. Completing each level inevitably requires skillful manipulation of the rules. As the game progresses, new words start appearing, introducing ever more complex mechanics. Often, the player must find out by experimentation the unexpected ways in which various rules can interact. "Undo" and "Restart" commands are available in case the player finds himself in an unwinnable situation.