Little Extinctions

Natural selection on a shrinking planet

Little Extinctions is a 2D natural-selection simulation set on a warm planet. Small, round gray animals spread across its regions and developed into red, blue, and green subspecies. Red animals grew larger and stronger, blue animals learned to cooperate in packs, and green animals produced more offspring. A drought shrinks their habitat until the three groups meet in one region, unaware they share an ancestor. You watch their populations as an alien biologist.

Genes and behavior

Each species has three gene loci: Physical, Cognitive, and Reproductive. Each ranges from 0 to 255 and determines a creature’s color, name, and 19 traits, including size, speed, vision, and offspring count. Young creatures inherit a mix of their parents’ genes, sometimes with a mutation; a new color marks a new species.