Similar to the Zombies mode in previous iterations, Call of Duty: Ghosts has its own bonus mode called Extinction. In Call of Duty: Ghost's Extinction mode, you team up with three other players to outlast waves of progressively difficult aliens, moving to new locations destroying hives and using acquired cash to buy new weapons, ammo and explosives.
Thing is, you can't play this mode right away. That said...
How do I unlock Extinction Mode in Call of Duty: Ghosts?
Simple, really. To unlock Extinction Mode in Call of Duty: Ghosts, play through the first mission in the Campaign (what we did), or an undisclosed number of matches in multiplayer, according to some players. Really, the single player way is the best option. Check out this easy step-by-step to unlock Extinction Mode.
Now it's time to lock and load.