Perform 50 Hat Shots

Make your first kill as a rookie (in Cause and Effect mission)

You were invited into your girlfriend's house.

Complete the game on Casual

In the final duel with Maddox, kill him with the first shot ("No Loose Ends")

Complete any single player mission without using med kits, but taking damage

Complete Act 2

Kill 30 enemies using your sidearm

Kill all enemies in the beach houses without causing an alarm ("Leave No Man Behind")

Kill 25 enemies using thermal or night vision goggles

Rescue the friendly ("From Out Of Nowhere")

Kill 50 enemies while holding your breath

Gather information on Raul Menendez' suspected terrorist plot.