As leader of a prehistoric tribe, it's your job to keep your people fed, housed and safe.
But before long, you discover that this paradise is dangerous: natural disasters sent by jealous gods can wipe out huge swathes of your island, destroying your hard work. It's up to you to decide how to portion out work and prayer: do you send that spare villager to gather much-needed food, or to pray at the Fire God's shrine? Maybe those prayers will stop any future volcanic eruptions - which is good, right? But if your food drops too low, your people start dying.
This is a short game, over in about 20-40 minutes depending on how you play. In that time, the player goes from a tiny tribe of 2 people to an island swarming with villagers, covered in temples and assailed from all sides.