Amazingly addictive!!! Every time I say I'll play for half an hour, I end up spending half the night playing!
Anyway, I start with the tutorials, expecting them to be a lot like other tutorials where they give you extremely basic instructions, then when you go for the campaign, you realise that you're swamped with details they didn't mention, as well as a lot of other difficulties that you'll simply have to find out for yourself. So, you can imagine my surprise when, after completing the tutorials and starting my first game, I discover that I've got more or less a good overview of the game and how to play it.
Within an hour, I'm hopelessly immersed and I've lost contact with the rest of the world. That first day, I spent the entire night trying to defend my home planet and other developed colonies from the onslaught of several hostile alien races. I didn't even realise what time it was till my alarm rang and I realised I had to go to work in an hour.
The graphics are pretty good for a turn-based strategy game ( 3D engine, but thats the least you can expect from any game these days). The sound effects, from laser blasts to space stations are standard, meaning they're a lot like Star Trek - Star Wars sounds. You've also got some ambient sounds which keep the galaxy alive, and without them it wouldn't be the same, since you'd be going around in the galaxy in relative silence.
To keep it short, for any strategy gamer, this game is purely and extremely addictive. Its relatively simple (at least simpler than Civilization IV), since the tech trees are just one line, and don't keep branching out then fusing back together somewhere further down the line. Also, developing planets is straight forward, and you won't be spending any significant time keeping track of endless statistics or the like. Instead you'll always be waiting for, wondering about, and wanting the next turn (where you're expecting a tech to be completed, or a battleship to be constructed, or maybe an invasion army to reach its destination, etc....). Trust me, this is a game you don't want to miss.