Click on the empty tiles to the left to construct buildings, use them to defend your base from enemy and to produce units to attack them. All structures are upgradeable, which makes either them or units they produce more powerful.
Your goal in this defense game based on StarCraft is to play as the Zerg Overmind and build up your defense and survive the combined Terran and Protoss attacks.
Lead rebel forces to free the galaxy from the Empire's tyranny. Build and upgrade turrets, power stations, refineries, use air raids to defend command center from attacking enemy forces.