In this paper, we present an interactive game for a large public display. Our focus was on experimenting new ways to enhance the effectiveness of a large, billboard size, display by adding a collaborative interaction mechanism for a user crowd. Working with a pop festival organizer, we developed a technology proof-of-concept of a multiplayer raffle game supporting crowd interaction with a large public display using an air-filled ball, equipped with an accelerometer and a barometer, as an interaction device. We experimented on its possibility to engage festival audience in live pilots in two occasions. Our observations showed that the audience enjoyed the raffle game and participated willingly. In addition, advertisers found the solution interesting.