Amazingly, Firaxis got everything right. Changing anything when it isnt broken is always risky
The AI is improved and no longer cheats so obviously, at least not until the difficulty levels ramp up – but the game is candid about that too. Building cities feels just right – it’s no longer punishing to have more as in Civilization III, but there are effective deterrents to trying to spam the entire map with them as well. The various ways to win a victory, whether through domination, global conquest, a space race, culture and so on, are generally balanced and feel right. Wars are often long and difficult, and victories can be Pyrrhic, but they’re not so grueling as to be discouraged. The civilization traits, like Creative, Organized and Aggressive have meaning for both the behavior of the civilization and in terms of bonuses. The bonuses are just the right size – large enough to have a noticeable effect on gameplay and to influence the player’s strategy, but small enough as not to be overwhelming. Consequently, a civ that doesn’t enjoy the Aggressive trait need not fear war with another that does, but having the Aggressive trait would help win a few battles. The AI also tends to build itself around its traits, but again, they don’t blindly focus on what they do best.