Defeat 4 enemies with the same explosion (all explosive items and weapons apply)

Defeat 50 enemies with headshots

Find a Journal Note

Defeat 20 enemies with headshots

Hit all targets in the attic with the toy gun

Finish the Game on Normal Without Changing the Difficulty

Kill 30 Enemies with the Tau Sniper

Find 40 Treasures

Play in the Swimming Pool on the Cruise Ship

Kill 100 Enemies with Headshots

Find 20 Treasures

Defeat 50 Enemies with Hand-to-Hand Combat