movements. The playground doesn’t need any significant alteration except for installing sensors enclosed in boxes in order to detect various movements such as tilt, motion, and rotation. These boxes are quite compact and do not affect the handling of the various playground devices.

Lalalab designed a series of mini-games for Hybrid Playground in which teams of four players can play simultaneously. Each team has one leader, who handles the PDA with the digital game, and three players wearing identification bracelets. Each team has a specific color and an avatar in the digital game. These roles are interchangeable at any moment during gameplay. The players wearing the bracelets are tracked in the playground and perform the physical actions of the game. The fourth player, or leader, oversees the unfolding of the game on the PDA screen and acts as a guide to the other team members, giving them precise orders to undertake the actions that each game requires. Each element of the playground has various mini-games with different degrees of difficulty that players have to overcome. The movements of the children engaged with the physical devices of the playground generate the input required to control the avatars in the digital game.

Because the game system of Hybrid Playground is adaptable and allows for a wide range of possible game scenarios, Lalalab is interested in having game designers create original games for their platform. They asked me if I would be interested in

designing a game exclusively for Hybrid Playground.

I became very interested in the challenge of designing a gameplay experience that would go beyond the successful mini-games. The feedback and experience they had testing those games for Hybrid Playground with children had been overwhelmingly positive. I felt that since their platform was successful with mini-games, the challenge of creating a game with a higher learning curve and more demanding gameplay was similar to the challenges I faced designing Virtual Ground.

My main inspiration for designing what eventually became Flying Machine was the work of Swiss artist Jean Tinguely, whose elaborate kinetic sculptures resembling useless, overly complicated machines, have fascinated me ever since I saw a retrospective as an eight-year-old growing up in Switzerland. The idea of controlling a virtual machine using elements of a playground seemed to be a possible direction for a game played by children between the age of six and nine—the main age group targeted by Lalalab for Hybrid Playground.

I decided on the design of a machine grounded on the floor, which a “crew” of children would have to “lift.” Each child, controlling a different part of the machine, takes it through a coordinated effort to reach an altitude of a thousand meters, avoiding increasingly menacing obstacles along their way.

The machine consists of two balloons that have to be inflated for upward movement, a propeller for horizontal movement, three air cannons aimed at dis-

sipating clouds, and a main cannon shooting at the bombs hidden behind the clouds (as shown in Figure 3a).

The children control the various parts of the machine using the playground elements as input devices. The machine’s state and movement are represented on the PDA screen held and closely monitored by the “captain,” who shouts orders to his crew: “left balloon, inflate faster!”; “propeller, go right”, “air cannon, shoot!”, and so forth (see Figure 3b and Figure 3c).

Every time a balloon collides with a bomb, the machine spins downward and declines in altitude, signaling to the children that it’s time for them to switch roles, each now controlling a new part of the machine by moving to different elements in the playground, with another child taking the role of captain (Figure 3d).

The main challenge of the game is the careful coordination of all the different parts of the machine through vocal communication between the captain and its crew. Children activating the different sensors cannot see the consequence of their actions and thus have to rely entirely on the captain’s orders. In turn, the captain must anticipate the movements of the machine, balloons being inflated to the point where they explode, clouds hiding bombs that need to be dispelled, bombs that need to be shot, then communicate effectively with timing to his/her crew the necessary actions they need to accomplish given the current on-screen situation (see Figure 3e).

To prevent the game from being overly difficult and frustrating for the children, I decided to implement a dynamic