Bought it yesterday. Not half bad.
It has some great outdoor levels like Tribes 1 and 2. (Arid is a good example) It also has a singleplayer campaign with good AI and a plot that hops between various characters and times.
A lot of the missions are impressive such as one where you play as one of the characters when she's a kid, escaping from the Imperial Palace when it's under heavy attack. You're trying to survive without any armor, weapons, no jetpack, and you're too short to reach things. Sounds frustrating, but it's beautifully scripted and put together.
Another mission lets you play as a Cybrid assassin. (they're the big badguy robots from Earthsiege and Starsiege, the mech games in the universe) Disabling key parts of a base and then hunting down a person.
Of course, then there's the StarSiege: 2845 mod coming soon. Fliers, mechs, infantry, tanks, the whole works in a team warfare game.
