Strange Prehistoric Roleplaying
From the introduction:
Player characters form a small band of hunter-gatherers. Most people at this time lived in small groups, ranging from a single family of maybe four individuals to larger tribes of several dozen. Life was largely nomadic at this point, with settlements and camp-sites only temporary before the people moved on to somewhere else. In this way, player characters will be just another group of people trying to survive as they wander across the landscape.
What sets player characters apart, however, is daring.