Complete every missions on Heroic difficulty.
Complete every missions on Normal difficulty.
Complete every missions on Legendary difficulty. (unlock the Gold Shotgun)
Play arcade mode with 3 bonuses in your package.
Use a Continue Token for the first time.
Buy a new Helmet in the store.
Die for a total of 99 times or more.
Complete a Weekly Challenge.
Upgrade any Weapon or Vehicle for the first time.
Get the Sergeant rank.
Get any Commendation to Iron level.
Run for a total of 250,000m.
Fully upgrade any Weapon or Vehicle in the store.
Find the 8 hidden Skulls. (unlock the Flaming Skull helmet)
Complete 5 Weekly Challenges.
Get any Commendation to Max level.
Get the General rank.
Run for a total of 500,000m.
Buy 7 helmets or more in the store.
Get a total of 250 Laser Kill medals or more.