Ammo is a single-shot game aimed at telling one type of story. You pretend to be a character whose world has just been plunged into war against an enemy only you and a handful of others are intimately familiar with. The game begins with a scene dedicated to showing how cool you are. Then a scene where everyone playing the game comes together and meets each other (maybe for the first time, maybe just like normal). Then the badguys strike! You fight them with your guns, and the rest of the game goes from there.