Enormous Insect.
The world has been attacked by enormous insects that appeared out of nowhere. Most of the adults are 'out of commision'. The children of the world have been left in their destroyed home to fight off these....things that have dropped in numbers since their first attack. No mechas, just good old-fashioned guns, tanks, rockets, and whatever else these kids can dig up. Most kids live in small, nimble groups, but there is new information about larger groups building armies to reclaim the land that their parents had left to them. You are a part of a small, nimble group. After battling a massive bug in the ruins of Atlanta, Georgia, your team is discovered by a dispatch squad of kids from the only large group in America, centered somewhere in the middle of the old country. At the promise of food, shelter, and more weapons in exchange for your skills, you leave your team for another. As you are flown (yes, kids have learned to fly in order to survive and stuff) via helicopter to the American group HQ, you are informed of your new position in the highest ranking military squad. You go out on missions to rescue other survivors or to hunt bugs, whatever you are ordered to do. However, as you and your new team are handed down....questionable orders, you begin to wonder if there isn't more to the plans of the higher-ups other than 'reclaiming what is rightfully ours while saving others like us'. You begin to see a world of decieving plots, honorless politicians, and empty promises that make you question your own role as a tool for giving false hope to survivors and for 'squashing selfish rebel groups who do not care for the future of mankind, only themselves and their ideas of so-called freedom'.