1) Press play. Land will be generated. 2) Press space to generate a new terrain if you like. 3)??? 4) Place 5 rivers by clicking where you would like the source. The river will flow down hill towards the ocean. Fresh water is very important for your critters. Make sure they have a lot. 5) Place 2 herds of herbivores. Watch them populate the Earth. 6) Place down a carnivore pack. Watch them control the herbivore population. Green earth has more vegetation than brown/grey earth. Herbivores will eat the vegetation but it will replenish after time. Only one feature is passed down to the child generation. Each child is up to 5% larger or smaller than its parent. Larger Herbivores: 1) Make bigger targets 2) Consume food faster and therefor produce more offspring. Larger Carnivores: 1) Move faster. 2) Are more likely to intersect with an herbivore and therefor make better hunters 3) Require more food to survive. 4) Take longer to have children.