This game have received a lot of praise over the years, and I enjoyed it as well. Still, there's some flaws at this game. Basically, it's a space shooter, and a great one as well. it never gets too complex, most of the missions is just "shoot the bad guys and make sure we don't get hurt"...
One problem is the overall universe and plot, which is narrated some extremely boring briefings, that you will want to skip instead of plowing through long pages of space-military-blah blah forever. Other than that, pretty nice game, and do yourself and install FSopen, that will improve the graphics radically, and give you the opportunity to play new campaigns.