Sid Meier's Alpha Centauri Complete with Alien Crossfire Expansion Design Your Own War Machine: Custom build fighting units that meet your missions specific needs. Diplomatic Relations: Dynamic personalities react individually to your actions. Infinitely Replayable: A random 3D world generator, unlimited strategies, five paths to victory, six levels of difficulty. Includes the Alien Crossfire Expansion Pack: Adds 7 new playable factions, new technologies, new secret projects.