I'll tell you about just one aspect of this game, which made me sell it rather quickly - horrible, horrible interface. If you ever played Civ3 or 4 you have seen the best. In Civ all mechanics are completely transparent, you can actually PLAN IN ADVANCE to build something or execute some STRATEGY.
Not so in GalCiv2, oh no. Want to create some building on a planet ? Want to know how long it will take ? Tough luck, you will only see the ETA number when you actually order the thing you want. Before it said "Never", but when you order something its suddenly "5 weeks", what ? Same with ships, impossible to predict what affects build time. Same with research, laboratory description gives you one number, actual "beakers" on the planet is another number, and planet summary gives you the third number. All different numbers, of course. Tech tree is uninteresting, and if you discover that some component requires another tech - the game will not actually tell you what that other tech you're supposed to be getting.
Sorting planets/ships in the list is horribly inefficient and secretive, too, even MOO2 had better colony list back in '96.
I cant tell you more about the game, because i was so disgusted about not being able to understand how everything works, i didnt play it much at all. Complete lack of game mechanic transparency prevents it even remotely being in the same league as Civ games. Dont think that the mechanics will be explained in the manual - they wont be, manual is completely useless in that regard.
Maybe there's some hidden beauty to the game, but its a b**ch to control, thats for sure. People who praised Stardock for creating good interfaces must have been high or something. I await Elemental with gravely suspicions.