4X games are great fun when fully developed. 4x stands for explore, expand, exploit and exterminate and lots of great games has been given this lable (Master of Orion etc.)
The tricky part for the developer is that it basically is four games in one, and each part has to be fun in itself and contribute to the whole.
Now, with online games you need to balance the different x's. If exploring is important you will end up eith a game where the biggest challenge is to google for spoilers, if its not important at all you loose one side of your game.
