CityFireflies is an urban game originally made for the Medialab Prado media-facade in Madrid which uses a light source as a mean of interaction.
The game consist on a series of levels where enemies try to invade the square where the players are. The user must use a light source which all of us have, the light emitted by the phone screen, so rapidly the player can enjoy the game in this huge 15×10 meters Media Facade.
Before staring to create the game, we had something very clear in mind, we wanted to focus in the user experience for digital urban games. We discarded using active devices that sends information to the screen since is overcomplicated to set it up in urban context and internet on mobile phones, although is here, not everybody has it, and we wanted EVERYBODY to be able to play this game, kids, youngsters and granpas :)
The other solution we thought about was tracking the user with cameras but most of the times the result is not good enough, specially when lots of users are playing in a reduced space and light condition varies. For these reasons we came out with the idea of using light sources as a controller, so turning on the phone screen works perfectly even with a huge number of players!
The game was showed in the Piksel Festival 2011 in Bergen, Norway. One day indoor due to the rain, one day outdoor.
If you are curious to see how it looked like in only 24 hours of development, check it here :)