A nameless protagonist is sleeping when a monstrous hand appears from under his bed to nick one of his slippers. Awakened and annoyed, he pursues his precious possession through the giant hole... to unwittingly enter Full Pipe! Getting the slipper back is an easy task, but the little man is soon trapped in a complex system of pipes - all leading to different cells with unusual characters. Shown from a third-person perspective with drawn characters against pre-rendered 3D backgrounds, progress is achieved by collecting items, solving puzzles and playing mini-games.
Many puzzles are illogical, just like the game's world, and inventory-based, though a few of the puzzles are presented as arcade mini-games. Collected items are shown at the top of the screen. The game's actions are controlled by the mouse and there is an in-game map which can be used to move directly to the selected cell. Full Pipe consists of 39 scenes, divided over three floors. There are 45 characters, with their own behaviour and names such as Hand Thirty For, Hare-the-Nooksiter and Polly the Janitress. There is no dialogue however - by interacting with the creatures you need to find out what their purpose is.