The tasks that a player must accomplish to survive are:
Obtaining food: hunting or scavenging
Water: don't being very far from fresh water
Migrating: looking for better places, more food or water, a mate, less dangers as people, pollution,
Mating and growing chicks, actually there's the goal of everything. Males have to put other males out of his territory, look for females and seduce them. Females has easy to get a partenaire, but they will have to take care of their kitten until they are strong enough to be on their own.