Gain the loyalty of the thief

Perform 30 headshot kills with any weapon on humanoid targets

Successfully recruit Archangel

Retrieve mineral resources by scanning and probing a planet in the galaxy map

Return to active duty

Modify a weapon.

Visit a store in the single-player campaign.

Return to active duty.

Become a Spectre

Attend the final ceremony.

Complete Riley's interrogation.

Kill Vaas.