1. The game causes the player to play as a 'volunteer'. Volunteers, in past "Last Stand" entries were people thought to be immune to the zombie virus. That status has changed here. What does every volunteer share in common with one another?
From Quiz "The Last Stand: Aftermath" General Quiz
Answer:
They are doomed to die
Volunteers are people who came into contact with the virus somehow, but unlike others, didn't immediately turn for one reason or other. However, as the virus has been around for multiple in-game decades, this immunity is slowly wearing off. This becomes an integral part of core gameplay, as the player's volunteer will eventually die to their progressively worsening infection, prompting the player to quickly get a volunteer to an objective before they die.
If the volunteer ends up making it to the end of the game, they will be instructed to be a Guinea pig for a serum that the Colony is developing. The effects of this serum will always be lethal, meaning even if the player were to play absolutely perfectly, their character will always die at some point, guaranteed.