4. Starcraft II: Heart of the Swarm
Starcraft II: Heart of the Swarm is the second chapter of Starcraft II. Set after the events of the first game, Wings of Liberty, players will now assume control of Kerrigan and the Zerg and experience her story.
Spanning across 20 missions, the game will also offer some huge additions to the multiplayer game with the inclusion of seven new multiplayer units, and bring changes to many existing units and buildings.
More than just a thematic update, the game will also bring improvements to Starcraft II's graphics engine, with upgrades to the look and behavior of Zerg creep and all its environments.
You'll need to own Starcraft II to play this one.