Kill an Enemy While Playing as an Alternate Character Costume Other Than Drake

Kill 30 Enemies with the M79

Activate a Tweak

Finish the Game on Crushing Without Changing the Difficulty

Finish the Game on Easy Without Changing the Difficulty

Kill 20 Enemies by Shooting from the Hip (without aiming)

Kill 50 Enemies with the 92FS - 9mm

Kill 50 Enemies with the M4

Kill 30 Enemies with the Dragon Sniper

Kill 20 Enemies with the Wes - 44

Defeat 250 Enemies with Headshots

Kill 30 Enemies with Mk-NDI Grenades