Complete A Mission In Co-Op Mode (Any Difficulty Level)

Good guys stand up and take the heat.

Complete Mission 3 (Any Difficulty Level)

Kill 1 000 Zombies

Complete A Mission Without Dying

Fully Upgrade A Single Stat Of Any Weapon In Campaign Mode

Deal 20 combat damage to a player in a single turn in a game

Wield the knife in single player or co-op mode.

Complete the single player campaign on Supersoldier

Complete 6 levels on Supersoldier difficulty

Re-route the power in Eye of the Storm without being detected

Complete 6 levels on Veteran difficulty