That still makes it a pretty good game and one I will play for hours, but for what it is worth here are my gripes with the game. Bear in mind that I am not a good player, which (possibly?) marks me as a mainstream target customer for the game.
1. Terrain generation is still an issue on the 6th game of the series. Too many maps are still boring, or starved of what you need, to get a start worthy of playing. As it takes (seemingly) forever to start up, this is a real issue. If you are unlucky you might never really get started.
2. The AI, particularly early in the game, doesn't seem to play to win, it seems to be doing its best to be as irritating as possible. Ive had up to 3 civs march 30 hexes across the map to plant a city so close to my territory that two of them didn't have a clear hex around it. In occasional games, even on lower difficulty levels, for no apparent reason, civs attack you aggressively en mass, with surprising co-ordination with the barbarians, who will hurl themselves to death on your city walls, rather than capture a worker or pillage an AI civ much closer to them. While this does increase the difficulty, I have the difficulty slider for that.
3. Ridiculous trade agreements keep being offered to me, turn after turn. The diplomacy screen is slow, even if you escape out of it. I don't need to keep seeing offers for me to trade all my luxuries and gold, for open borders 20 turns in a row, from 3 civs. How difficult is it for the AI to stop offering stupid one-sided deals?
4. The game in general is hideously imbalanced everywhere. While this does create variety, I don't understand why it cant be balanced as well. Some of the abilities the civs have are so difficult to use, that they make the game frustrating. China's great wall is a case in point; there are so many restrictions on building it that finding 3 hexes in a row worth building the damn thing on, is a daunting challenge. The natural wonders, and great wonders are just as bad. I just can't see how it is difficult to balance these up, or at least get them closer. Even the basic unit types and their rock/paper/scissors effect on each other are not equal; ranged units are still obligatory, whereas you can easily go a whole game without cavalry or spear-men.
5. Religious warfare; surely a case of the emperor's new clothes, no one willing to tell Ed how much it sucks. I am not opposed to the idea of a religious victory, but not only does the system not begin to give a respectable representation of religion (not essential I know), but religious combat is just another version of military combat, with all the fun, complexity and interest taken out. The question isn't whether it is enjoyable, but how could anyone think it is enjoyable.
6. Spying. I've never really been a fan of spying, but it seems that that the designers can't make up heir minds about it. There is no doubt that spying can make a big difference in the game, but the spying game itself is so weak and tedious that it is just no fun to play. They had an opportunity to create a mini game sneaking spy units around the map avoiding military units and other spies, stealing technology or sabotaging stuff or assassinating great people, but instead we get a bunch of menus and text-boxes; Lazy work! Not only that, but there is no option to disable it any more.
7. Programming is not good; The game runs very slow, and there are still some ugly bugs. Units disappear, I cant promote units, with a promotion waiting, unless I move them, and basic stuff like clicking still taking effect even when the game is not responding. Note to all developers everywhere: You have a fast PC so you can develop games, but you still have to test it on the sort of machines your customers will use.
8. The start screen and main menu has features removed even from Civ5. The high scores table, and the ability to change the default create settings are gone, for no other reason than they were too lazy to include them. So you start a game and suddenly realize you forgot to set the speed to quick, so back out; start it up again; crap, I forgot to change it from random civ; start it again; lousy start, restart; start it again, oh crap, speed setting again! Give up!
So that is about it for me. I'll keep on playing, but I used to recommend civ to parents as a "good" game for kids. I just don't think these days it is enough fun to hold a child's attention. Most of my enjoyment is remembered I think. Can't help feeling that the game is going backwards in enjoyment, even as it grows in complexity.