This game is fine for casual gamers but not hardcore gamers, specifically hardcore strategists and tacticians.
I think that the reason why people are rating this game so highly is because they have no point of comparison since there are very few 4X space games on the market and most likely newer gamers never played the games mentioned above which came out in 1996, 2000 and 1999 respectively.
The first thing I noticed was that the game was still being patched as late as January 2008 ( even though GalCiv2 came out in Feb 2006 and even though mine was the Gold Edition V 1.5 ) so my first question was why? Why are people talking about bugs and game-design flaws on Stardock's forum? Where were all the beta testers? After reading the back of the manual I noted that there were no game testers listed! While trying to figure out who created the game, I looked through GalCiv2's Wikipedia, and the game was programmed by a team of only 6 coders!
The most obvious flaw in this game is that ship-to-ship tactical combat is non-existant. It's frustrating and insulting to watch a cinematic cutscene, where your ship floated around as if it were a puck in air hockey, as if your captain were drunk and chimpanzees were working in gunnery.
While designing custom ships I did ask myself, "how deep can this game be when the programmers invested so much time into giving the player the option of connecting components like engines and guns to different points on the ship? It has all the sophistication of lego, is the target demographic a bunch of 8 year olds?"
The campaign mode is a joke, it seems like it was tacked on as an after-thought and consists of "capture a planet". The story is lack lustre.
The sandbox game, strategically just seems like a rush game. The person who grabs the most habitable planets and climbs up the tech ladder the fastest, ends up the winner.
The graphics are good, the sound is mediocre, the cut-scenes for events and good, the sandbox customization is great. This game lacks strategic and tactical finesse and gets repetitive very quickly.
This game can be addictive, in the same way that a slot machine can be a time sink but once you get past the flashing lights and loud noises, it tends to leave one empty.