This leads to the issue of artificial intelligence, always a controversial subject in strategy games. The AI in Galactic Civilizations II differentiates it from other 4X games: It doesn't cheat, and it's very, very good at higher levels. It's also unique in that the AI doesn't treat the human player any differently than it does the other AI players. You can set the AI to a lower level to allow you to have fun while learning the game, but when you set it higher as you advance in your skills, the game doesn't respond by cheating. Instead, it employs more advanced (and devious) strategies, observing and adapting to your play. For example, at lower levels you could be trading and generally playing nice with a neighboring civilization that is rather weak militarily, while at the same time setting up military starbases and fleets of fighters in their vicinity, and the AI may continue to trust you. At higher AI levels it will recognize the signs of betrayal and take preventive or preemptive actions.

You can make some really cool--and really ugly--ships in the ship designer.
In fact, the AI will surprise you with the humanity of its style. You will be simultaneously surprised, pleased, and frustrated when you have almost defeated a civilization, are gloating over the resources that are about to be your spoils of war, and then see your victim surrender to another race that is more aligned to its ethical style just to keep you from taking it over. Or when you're at war with a race and are informed by a superior race that you're hurting their trade income and thus must be eliminated. The AI will watch you and adapt, and not always in a predictable way, even after having played many games. They'll seek out weaknesses and exploit them. At higher levels you'll be convinced that the AI is cheating, but it isn't: It is just diabolically clever at finding ways to optimize strategies. Perhaps the best compliment you can pay the AI in Galactic Civilizations II is that it will beat you in ways that you will respect and admire.
In addition to playing with the default ships included with the game, there's a very cool ship designer that'll let you make your own. And you don't have to use the various ships included in the game; you can design your own from scratch, using any combination of technologies that you have currently developed. There's also a large set of purely cosmetic parts you can use to create the ship of your dreams; users have posted screenshots of incredibly detailed and complex new ships that they have designed. Staying consistent with the theme of letting players play in their own way, you can successfully take the approach of designing fleets of small, fast, and pesky fighters that may be effective against larger capital ships if you choose your weapons wisely (defenses are effective only against specific weaponry). Conversely, you may prefer fighting with huge space dreadnoughts, or perhaps mixed fleets. Prudent investment in espionage can give you a crucial advantage in discovering what weapons system the enemy is building, so you can design the most effective weapons and shields to counter them. But be aware that the AI is likely doing some spying of his own.
While there is a plethora of game features that we haven't mentioned here, such as a galactic United Nations that raises issues that all races vote upon that impact your empire, extensive trade and diplomacy with other races, and much more, one that is worth highlighting and that follows the thesis of letting you have it "your way" is the completely open nature of the game's user interface. The game screens are stored in a directory and can be easily modified. The game is also designed such that there is no limit to the polygons it can handle; users are already showing off incredible Star Wars-based ships with extremely high polygon counts.

The evil squirrels! We're doomed!
There are, as in any game, some nits to pick: The technology tree could use beefier data on future techs; it would be nice to have the ability to select random races on startup; and there is no multiplayer (yet). But Galactic Civilizations II is a game that provides that "just one more turn" compulsion, and that appears to have the ability to stay fresh, surprising, and replayable for a long time. One of the greatest compliments is the comparison to Civilization IV that many people are making. Suffice it to say that Galactic Civilizations II is different in many ways than Civ IV, but stands next to it as one of the all-time best 4X strategy games.

Galactic Civilizations II: Dread Lords (PC):
