Extinction mode:
Successfully complete Mission 1: Ghost Stories in Campaign mode on any difficulty to unlock Extinction mode at the main menu. Alternately, reach Level 5 in Multiplayer mode. In Extinction mode, four players
fight aliens in a post-apocalyptic world.
Ghillie suit:
To unlock the Ghillie suit in Multiplayer mode, select “Weapon Challenges” to see if the “Chrome Barrel Master” challenge is active. If it says “Challenge Inactive”, go to “Operations”, and spend one Squad
Point to get new challenges. Repeat this process until the “Chrome Barrel Master” challenge is active. Then, complete the “Chrome Barrel Master” challenge to unlock the Ghillie suit.
Exploding alien dolls Easter Egg:
Start Chapter 1: Point Of Contact in Extinction mode, and obtain the sniper rifle. Find the “Gil’s Lodge Motel” neon sign in the first area of the game. Use the sniper rifle to shoot the letters “L”, “O”, and “L” (in order) in the word “Lodge” on that sign. If done correctly, the message “LOL” will appear in the center of the screen. *Note:* This may take a few attempts before it works correctly. Once the Easter Egg has been activated, for a short period of time, any alien shot will explode into golden stuffed alien dolls.