The prehistoric world does not forgive weakness. Alone or with friends, you start with bare hands: hunting, fire, stone weapons and a camp worth defending. Every night here has to be survived.
Having lost your tribe, you as the sole survivor, find yourself in an era of deadly danger and exciting adventures. You have to build yourself a shelter, make weapons, protect yourself from wild animals, and prove that you are not a prey, but a predator.
Build your shelter, craft tools, weapons, collect resources in different biomes to create whatever you need, and conquer the world as you see it.