The game's objective is to find a diamond worth 10,000,000 yen hidden somewhere in a three-story building. To achieve this, the player must pick up various items that can aid in their quest and avoid hazards that could lead to arrest or death if not handled carefully. The gameplay relies heavily on exploration and puzzle-solving.
The game features a unique two-stage input system where players must type a verb first, followed by pressing RETURN and then entering the corresponding noun. For example, "Open" would be followed by pressing RETURN and then typing "Door". The player can also use movement commands such as "forward", "back", "left", "right", "up", and "down" to navigate through the building.