[ckotchey]

For me, it's not so much things like the huge number of tech levels, ship components, and whatnot, but in the way that all these options actually creates so many different ways to play the game. There are many ways to achieve the same goals. For example, you can play by focussing on bombing planets, troop-dropping to overtake them, destroy ships, board ships, etc. So many different roads to travel to meet your goals, not not just the brute force of so many other games.