Kill 50 supply worth of units within 15 seconds in a Melee game.
Have 21 Zerg units morphing simultaneously in an Unranked or Ranked game.
Score the rank of Gold in the “Rush Defense” challenge mission.
Score the rank of Gold in the “Tactical Command” challenge mission.
Destroy an enemy Command Center, Hatchery, or Nexus while it is under construction in an Unranked or Ranked game.