Enemies and ships are yours to design in Galactic Civilizations II: Dark Avatar as you attempt to become the most powerful force in the galaxy. By customizing your opponents, you can alter their looks, personality, and strategy and then play against them. You may also design spacecrafts to save and use as templates, or assign them to yourself or another faction in game. For undercover operations, spies are now available for a fee, and can be used to sabotage such enemy functions and attributes as morale, research, production, and farming.

Though past editions of Galactic Civilizations feature unlimited planet colonization, this expansion relies on technological research as a catalyst for searching out new homes in environments that include radiated, toxic, aquatic, barren, and heavy gravity habitats. Furthermore, each civilization now comes packaged with a unique super ability. For example, the super-isolationist can slow ships that travel through its air space while the super warrior race receives extra combat units. Other content includes the option to enable or disable "mega events" designed to upset the balance of the game and your strategy, and the ability to mine neighboring asteroid fields for resources. Galactic Civilizations II: Dark Avatar also comes with a new campaign and mini-campaign, two additional races, and the option to research diplomatic treaties. ~ Gracie Leach, All Game Guide