Destroy an Atlas dropped from orbit.

Kill a brute while it's charging you.

Visit a store in the single-player campaign.

Return to active duty.

Complete Mass Effect 2 twice, or complete it once with a character imported from Mass Effect 1

Use the Omega 4 Relay

Obtain geth technology

Kill enemies with 5 different heavy weapons during the game

Help the Justicar resolve her mission

Thresher Maw defeated

Gain the loyalty of the Assassin

Fully upgrade a weapon

Gain the loyalty of the Cerberus Officer