Wings of Liberty was released alongside 2.0, an updated version of Blizzard's online system. It was announced prior to release that instead, the singleplayer campaign would be extended through expansion packs which focus exclusively on the other two playable races in turn StarCraft II: Heart of the Swarm, which focuses on the Zerg and was released in 2013, and StarCraft II: Legacy of the Void, which will focus on the Protoss and has not yet been released. All three races are available for multiplayer, however.
Unlike the original StarCraft, StarCraft II only includes a singleplayer campaign for the Terran faction, consisting of roughly 30 missions. The games return to a galaxy in turmoil between three warring species the Terrans, the future form of the Human race, the Protoss, an ancient race possessing incredibly powerful psionic abilities, and the Zerg, an insect-like, bestial race consisting of billions of mindless 'soldiers' controlled by a single guiding intelligence.
StarCraft II: Wings of Liberty is Blizzard Entertainment's 2010 follow-up to one of the most popular strategy games of all time.