Kill 50 units with a single Penetrator Round in the “Belly of the Beast” mission on Hard difficulty.
Call down 30 MULEs in an Unranked or Ranked game.
Destroy 4 Zerg Hatcheries in the “Zero Hour” mission on Hard difficulty.
Use the Artifact no more than once in the “All In” mission on Hard difficulty.
Kill the Brutalisk with lava in "The Devil’s Playground” mission on Normal difficulty.