Use the A.R.E.S. to kill the Brutalisk in the “Piercing the Shroud” mission on Normal difficulty.
Beat the Terra-tron on the Lost Viking arcade machine.
Complete all 29 Wings of Liberty campaign missions on Brutal difficulty.
Complete all mission objectives in “The Gates of Hell” mission.
Complete the “Shatter the Sky” mission on Hard difficulty in less than 25 minutes.