Gears of War 1

So, I saw that there was no Gears of War 1 topic. For those who haven't played it, humanity has spread to other worlds, and found a planet with a super fuel called imulsion. Humans decided to settle on this world, under COG or Coalition of Ordered Governments. Then, on one day, called E-Day, or Emergence Day, a species appeared called the Locust, who attacked Humans, and killed many. You follow Marcus Fenix and Dominic Santiago, and Delta Squad, who are trying to help the people of Sera, the fictional planet, from the unending Locust Hordes.