Kill 20 enemies melee-attacking from behind

Kill 10 enemies by aiming while hanging from a ledge

Find 35 treasures

Finish the game in Easy Mode

Find 30 treasures

Kill 50 enemies in a row without dying

Kill 20 enemies by shooting from the hip (without aiming with the L1 button)

Kill 20 enemies with the Desert - 5

Find 20 treasures

Find 15 treasures

Kill 20 enemies with a brutal combo

Find 10 treasures

Find the Strange Relic