This program creates small dark squares with behaviors and reactions, and fills the entire space with them. The squares must eat the tiny yellow dots as food or else they fade away and die, becoming food themselves. Programmed within each square is the drive to seek out food and eat it before another will. The size of the square determines how fast it moves. The larger the square, the slower it goes. Every second a healthy living square has a chance to reproduce.
The goal of these little beings is to survive and reproduce for as long as they can. When the program begins there are 4000 squares fighting for survival. This overpopulation leads to waves of famine that kill off hundreds of squares at a time, who then become the food for the next generation to live off of. Every time a square reproduces there is a slight mutation in its size for better or worse. Eventually the squares evolve to a size that is most effective at getting the food, and the population balances out to a sustainable level, though it is also possible for the evolution to not occur fast enough, leading to total extinction.