Ghost in the Cave (created by KTH, Stockholm; Octaga/ Telenor, Oslo; DIST InfoMus Lab, University of Genoa; DEI, University of Padua) is an interactive collaborative game using non-verbal communication.

Two teams of players can only use vocal sounds or body gestures to guide their avatar in a 3D world and to find three caves. Within each cave the players do an “emotional” task.
Each team controls its avatar either by singing into a microphone or by moving in front of a video camera.

Players not directly involved in controlling the avatars can participate too by influencing the music through movements.

By the look of the Video, it seems silly enough for me.

Via Pasta & Vinegar.