Evolve a creature.
See what survives.

A frozen ocean moon circling a giant planet, sealed under a kilometres-thick ice shell that blocks nearly all sunlight. Tidal flexing keeps a dark, salty sea liquid beneath the ice, warmed and fed by mineral-rich vents on the seabed. Gravity is light and the cold water oxygen-poor, so life clings to the under-ice ceiling above and the vent fields far below.

A vast arid desert under a fierce white sun and slightly heavier-than-Earth gravity. Liquid water survives only in deep aquifers and brief dawn dew; days scorch, nights freeze, and relentless wind drives the dunes across cracked salt pans.

A volcanic basin under a smoke-dimmed sky and Earth-like gravity. Sulfur vents and scalding mineral pools dot fields of cooled basalt; the air is thin and acrid, and heat from below — not sunlight — drives much of life here.

A warm, shallow inland sea under a yellow sun and Earth-like gravity. Tidal mudflats meet brackish lagoons; oxygen is plentiful in the water, scarce in the thick muck.