Complete all 29 Wings of Liberty campaign missions on Brutal difficulty.
Use the Artifact no more than once in the “All In” mission on Hard difficulty.
Kill 750 additional Zerg units in the “In Utter Darkness” mission on Normal difficulty.
Score the rank of Gold in all the challenge missions.
Kill 50 units with a single Penetrator Round in the “Belly of the Beast” mission on Hard difficulty.