Starcraft II inclueds two parts, StarCraft II: Heart of the Swarm and starCraft II: Wings of Liberty. StarCraft II: Wings of Liberty is a military science fiction real-time strategy video game developed and released by Blizzard Entertainment for Microsoft Windows and Mac OS X, and StarCraft II: Heart of the Swarm is an expansion pack to the military science fiction real-time strategy game StarCraft II: Wings of Liberty. StarCraft II: Heart of the Swarm's expansion includes additional units and multiplayer changes from Wings of Liberty, as well as a continuing campaign focusing on the Zerg race, following Sarah Kerrigan in her effort to regain control of the swarm and enact her revenge on the Terran Dominion's emperor, Arcturus Mengsk.
The game has 20 missions in the campaign (plus 7 evolution missions which determine how the capabilities of zerg units get upgraded), and continues the story from Wings of Liberty. The player plays from the perspective of Sarah Kerrigan, recently returned to her human state by Jim Raynor.