Use the Artifact no more than once in the “All In” mission on Hard difficulty.
Kill 50 units with a single Penetrator Round in the “Belly of the Beast” mission on Hard difficulty.
Destroy 5 units with a single Neural Parasited unit in an Unranked or Ranked game.
Score 500,000 points on the Lost Viking arcade machine.
Complete all 29 Wings of Liberty campaign missions on Brutal difficulty.