Artificial life system based in Genetic Algorithms.
Each individual of the population has several parameters like its speed, how long until they are hungry and the speed of reproduction. All of these modifiers are inherited by its offspring and therefore only the fittest individuals survive. They die of hunger, or by being too old. This creatures interact with the user through sound, getting scared each time that a loud sound is produced. This characteristic forces them to run away getting far from the food sources and from their matting partners. Therefore, the user has to decide whether to remain silent and let the population evolve, or to play with them and lead them to an early death. This is a metaphor of our interaction with the real environment, where we must decide to fulfill our selfish impulses or to allow the species to continue its existence.