Gain the loyalty of the Cerberus Operative

Successfully shut down the rogue VI in Project Overlord

Successfully recruit the Krogan

Complete a mission discovered by scanning an unexplored world

Obtain 10 technology upgrades

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

Successfully recruit the Professor

Unlock 15 new Mass Effect 2 codex entries

Perform 30 headshot kills with any weapon on humanoid targets

Personalize your armor

Completed the Second Episode.

Get 10 kills using detached turrets in any mode.

Kill all but 1 of the neutral prisoners in Dark Energon.