Kill 20 Enemies with a Single Punch After Weakening Them with Gunfire

Kill 10 Enemies with Grenades While Hanging

Defeat 250 Enemies with Headshots

Kill 50 Enemies with the Micro-9mm

Complete one Cooperative Multiplayer game

Fall off 20 times in any level

Stack a weapon with 3 of the same upgrades

Kill 50 Enemies by Melee-Attacking from Behind

Defeat 20 enemies with the Pistole

Defeat 20 enemies with gunfire by aiming while hanging

Find 20 Treasures

Finish the Game on Crushing Without Changing the Difficulty