One of the best games I ever played. Seriously. Space sims are not my favorite genre but FS1 and especially FS2 are the remarkable exceptions. It is highly narrative. It's very atmospheric. It shows stunning graphics (and if you use Freespace SCP's graphics improvements then it even gets ahead of the majority of modern space sims). And the player never gets bored thanks to a diversity of mission objectives and battle situations. And again it's one of the most narrative action games though it doesn't even have any in-game characters. But the story is very sophisticated and it constantly keeps player in anxiety.
This game is a remarkable example of the now-dead (well, almost dead) space combat genre. Though I wouldn't say that it changed the established views on genre or something like that. Actually, it's just very well designed. The essence of the game is simple: Freespace has no features like free-roaming or trading, but it can boast a variety of action-packed missions linked by a rich and atmospheric storyline (plus astonishing soundtrack and pretty nice graphics for 12-year-old standards). Rush dogfights, dangerous enemies, and a variety of objectives (escort, assault, recon, bombing...) - every time you should choose the proper tactics to survive and fulfil your current objectives (but luckily there are no such tiresome scenarios like "move there and spend 5 minutes, then move somewhere else and spend another 5 minutes only for being suddenly killed at 11th minute".) Сombine this with a solid storyline and deep atmospere of fear and despair (as the Shivan armada advances through Terran-Vasudan space) and we get a perfect sci-fi action thriller in space. Unfortunately, the Silent Threat expansion is half-a-crap (although there are some good missions in it as well), but this has no concern with the main Freespace campaign.