Emperor Blue Monkey says: "Aliens are attacking the world. They obviously despise our hamburger devouring, war mongering and TV addicted asses and want to go permanently camping in your grandma’s backyard.
Luckily, there’s a secret agency that knew about them all along and has made preparations for us smart apes to fight off these ugly, reptilian like beings. Their tech is at least a century ahead of ours, meaning they can easily vaporize us to hell… But, being the versatile creatures we are, we can adapt and we can learn from their knowledge by collecting aliens dead or alive and pieces of their equipment. This agency is called X-COM, and it operates worldwide."