Kill 20 enemies melee-attacking from behind

Kill 20 enemies with the Desert - 5

Kill 50 enemies in a row without dying

Kill 20 enemies with Mk-NDI grenades

Kill 30 enemies with the Dragon Sniper

Kill 10 enemies with grenades by aiming while hanging from a ledge

Finish the game in Normal Mode

Kill three enemies with one explosion five times

Kill 50 enemies with the PM - 9mm

Finish the game in Crushing Mode

Kill 50 enemies with the Moss - 12

Kill 100 enemies with headshots

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