It's essentially a land grab to collect the resources needed to build camps and settlements, and to sell metals (copper, silver and gold) for VPs. The tricky part is a mancala-style mechanism for using your collected resources, and the balance between building up a large collection for a blitz on the various VP generators vs. using smaller collections for less but more frequent VPs.
I really liked this. It looks gorgeous, and has enough variability in setup to make every game different. Fantastic!