You are the dungeon overlord and swarms of heroes are invading your lair, attempting to steal your gems. You must stop them by building creature lairs, traps, and sending your avatar out to defeat them.
Take control of the Stone Age general, scout out your enemy, find their weakness, gather your soldiers, and march on the enemy village. Victory will require total annihilation of the enemy faction; leave no one and nothing alive.
Grow your own tribe from first human-primates era to a first recognized ancient civilization. Develop your primitive encampment to a flourishing place. You need to grow population, manage workers, research technologies.