Tribes Vengeance - Destruction. Chaos. Retribution.
Vengeance's single-player game adds a new dimension to the Tribes universe, which puts several human clans, an alien race, and a race of robotic assassins at each other's throats. In the single-player game, we finally learn why the Imperials are trying to crush the Phoenix tribe, and why the Blood Eagles (themselves former Imperial soldiers) broke away under the leadership of a former Imperial general.
The story line, which up to now has existed solely in fan fiction, is a bit forced at times but nevertheless adds a new dimension to the game. In some ways, the single-player game is reminiscent of both the best and worst aspects of the Godfather films: The story line jumps back and forth in time (sometimes disconcertingly), and it focuses on a wide range of interrelated characters with competing interests. I'm not sure I care all that much about the backstory--but being able to play a little Tribes on a long flight, when you can't connect to the Internet, is far superior to a careful, hours-long examination of the Sky Mall catalog.
The single-player game does, however, introduce the novice player to every weapon, pack, vehicle, and feature of the game--which is just as well, since the real action is out on the multiplayer servers, where you fight teams of real players