This expansion adds two new clan decks, the Trajanas clan (lvl 7) and the Flavian clan (lvl 8), together with 4 new nearby island cards and 2 distant island cards and two new ships per clan.
The Trajanas clan is all about paying the resources matching the type and amount of corresponding locations. So when in the beginning buildings are cheap, further on in the game they will become more expensive.
The Flavian clan adds the element of foundations to the game. With the action HARVEST or through another action on a specific card you may flip cards to be foundations, which can be used in order to build other cards and give you an additional point per set in the end of the game.
These new decks add a lot of newness to the base game without being much more difficult to grasp. I mean this as a good thing, especially when you want more variety. I really like what they did with the foundations, it's a new element to the game that feels good.
A copy of this game was provided to me by White Goblin Games for the purpose of writing this review. My opinion however remains my own.