An ecosystem can be understood as the interactions between a collection of organisms and their environment. It can also be understood as a network of energy flows that is manifest in these organisms. Tiny Bricycle is an energetic utopia. Another exploration of resource recycling in artificial ecosystems, in this case the loop is closed and 100% efficient.
Agents are defined by their genetically encoded preference for either bright or dark pixels. They survey their local pixel landscape and move to a spot with sufficient resources. In this world consuming resources means altering the brightness of the pixel you inhabit: bright-pixel-eaters seek bright pixels and turn them darker and dark-pixel-eaters seek dark pixels and turn them lighter. They also leave a trail by altering the hue according to their preference value.
In this Best of All Possible Worlds resources never run out. On a blank white page a population of bright-pixel eaters thrives initially. As the image darkens, dark-pixel eaters evolve, eating up the dark pixels and making the world bright again. On a small page the population oscillates, given enough space the two tropes persist in symbiotic harmony. If only life were so simple.
I am not sure why it looks like moldy wallpaper. Perhaps it says something about the evolutionary supremacy of domestic fungus.