Cultural influence is one of the best ideas in GalCiv especially because it offers an alternative path to victory other than the traditionnal military conquest. Unfortunately the game mechanics in this area, even if well thought, remain too predictable as soon as one is a slighly experienced player. Basically once you reach a certain cultural advantage, enemy planets begin to defect one by one, without reason. It's kind of "black and white". Moreover a player or an intelligent AI always has the opportunity to declare war to a culturally powerful civilization so that you have to build a sufficient navy anyway. Once you get the ball rolling, it's basically over. I do not even talk about the Cultural victory condition, that I always disable at the beginning of the game.
That being said, I think the cultural thing lacks a dramatic element. There is no surprise basically and there are almost no interactions between influence and other concepts of the game. I'd like to see thoses aspects enhanced in GalCiv II so that cultural games become as exciting as military ones.
First of all, there should be other consequences than a planet merely defecting to another civilization. It should not be "black or white". Defecting should be of course the climax of cultural assimilation but this event should not happen without precursory signs and/or specific triggers. A happy prosperous free planet in a peaceful empire, even if the population is fond of foreign customs or goods, has no reason to make such a hard and hazardous decision which could trigger a full-scale galactic war. For instance, a declaration of war, a change of political regime, a revolt due to low morale, the defection of another planet, maybe even the closing of a trade route (that boosted the local economy or with the admired civilization) could be interesting triggers for defection. Tests should be mostly performed at those occasions. This could lead to interesting diplomatic and polical strategic choices : should I take the risk to cancel this trade route, to start a war, to change my internal politics ?
Then there should also be other consequences than the mere defection. For instance :
- (Slightly) lowered morale
- Need to establish a trade route from this planet to the admired civilization
- Emigration
- Bonus to espionnage for the admired civilization against you
...and so on.
Wa could also imagine several levels of cultural domination for a given planet, maybe even a percentage from 0 to 100. The rate of change and the current level would be influenced by the intensity of the cultural expose, the morale of the planet, the nature of the central government (an Imperium is repulsive, a permissive Federation is attractive), the diplomatic relations between the civilizations, an ongoing war (a winning war against a common foe retighten the links between citizens, a losing war can cause a country implose), etc.
When one or several planets defect to another civ (fo instance after an unjustifed declaration of war), there should also be leaks of vital technologies and even starships defecting at the same time. They could for instance be selected randomly, with a probability depending on the proportion of defections. This could give a culturally dominant but military weak civilization a good hope to survive a war if the culturally weak but military powerful civilization attacks it beacause of the cultural threat it represents.