I love Race for the Galaxy and acquired the most recent expansion for the game called Xeno Invasion which is Arc #3 for the game. This expansion will require that you have the base game and cannot be mixed with the other 2 arcs but is meant to be a stand alone game. As with the Arc #2 expansion called Alien Artifacts, Xeno Invasion can be played with the new cards alone or you can add in the new mini game where you will have to also fight off waves of Xeno’s who are invading your empire.