Gameplay consists of waiting and watching.  From a computer monitor, observe a recorded video loop of another room. When someone passes by a spot in that room, a shadow will appear on your screen rather than an image of the person. Click to snap a photo. If the player misses the opportunity or clicks after the shadow has passed, the other “player” receives a point. If one successfully photographs the shadow, the player receives a point. This game is to be played with people who don't know they're playing.  Although the game has a feeling of surveillance, it is only the proximity readings on an IR rangefinder from which the player is receiving signals that are creating the shadow, giving the player the hint of another player's presence.