Zeus: Poseidon is an official expansion pack for Zeus: Master of Olympus. In this new expansion you you'll mine the mysterious mineral "orichalc," establish colonies in ancient Americas, Africa, Europe, and Asia, and trade with ancient civilizations. Zeus: Poseidon Expansion features 46 episodes in 8 new epic adventures,  new Greek gods: Hera and Atlas, new heroes Bellerophon and Atalanta, new monsters like Chimera, Echidna, Harpies and the Sphinx, and new unique characters (archers, spearman, and charioteers). The expansion also features new buildings, including Observatories, Laboratories, Bibliothekes, Museums, and certainly new Sanctuaries to the gods). You have to exploit new resources like herd cattle, cultivate fruit, quarry exotic stones, and craft items of orichalc, the peculiar metal manufactured by the smiths of Atlantis, and trade with Mayans, Egyptians, Phoenicians, Oceanids, and other civilizations. Just the same gamplay like in Zeus: Master of Olympus, only a bit more various. In addtion, Zeus: Poseidon finally includes Adventure Editor which allows you to create your own Zeus adventures in Greece or Atlantis. So if you are Zeus fan, definitely get this expansion, though there isn't much new things, in comparison with Zeus: Master of Olympus.