The most impressive aspects of Gods & Kings take place under the hood. When I started playing the original Civilization V, two aspects of the game frustrated me. First, my computer started struggling with even modest-sized maps by the Renaissance era, and the 20th Century was virtually unplayable due to excessive time waiting between turns. Second, the computer-controlled opponents were extraordinarily passive, only declaring war on me occasionally, and never on each other, which made the game more artificial. Both are improved in Gods & Kings. I was able to finish games on maps that had previously given me trouble, and the AI was more aggressive, and more successful in that aggression, than I had seen before.