While games with screens are ubiquitous, very little computer games rely on sound alone. Asteroid Attack is a game in which the objective is to dodge as many asteroids as possible, which you can only hear coming. Fired at semi-random intervals, the player dodges these asteroids by jumping to the left and right sides of a long wooden casing. Through ultrasound, the system determines if the player is standing on the correct side of the casing in order to dodge the asteroid.
The asteroids are represented by a sound that approaches the player through the left or right channel of the Bluetooth headphones that the player is wearing. This sound is divided between the left and right channels with a 77:33 ratio. A Doppler effect is added to generate a virtual 3D soundscape over the two channel headphones. We designed the synthetic sound with a relatively
low frequency to make it feel as if a large object is coming towards you.
Every hit generates an explosion sound on the side that is hit. The ‘shield’ can take up to three hits, after that it becomes critical. This critical state is portrayed by an alarm, which inhibits hearing the asteroids approaching and thus makes the gameplay even harder. When the shield is critical, a final hit will destroy the spacecraft and the game will be over.
A minimalist electro tune (synthesized in real time) provides a background sound with a somewhat ‘outer space’ feeling. This also makes it a bit more difficult to hear the direction the asteroids are coming from. Finally, for every three successfully dodged asteroids, the player advances one asteroid belt, indicated by a cheerful sound. In each successive asteroid belt, the asteroids come faster and faster.
In collaboration with Maarten Lodewijk.