Use the Artifact no more than once in the “All In” mission on Hard difficulty.
Complete all 29 Wings of Liberty campaign missions on Brutal difficulty.
Destroy all Protoss structures in the “Phantoms of the Void” mission on Hard difficulty.
Kill the Tyrannozor in under 1 minute after it appears in “The Crucible” mission on Hard difficulty.
Complete “The Reckoning” mission in less than 25 minutes on Normal difficulty.