EXTinction mod for Doom III

Backstory- Its the year 2420. Humans are at a relativley peaceful state with one another. A discovery was made. Somthing crashed onto the planet. It was a pod type vehichle. When scientists went to examine it, they found two dead bodies inside. When analyzed further, the scientists realized that these bodies were unearthly, and from another solar system. It appeared that the minuscule ship was pulled into Earth's gravity unintentionally, and the pod couldn't handle it. Fast forward 40 years. The aliens have been known about for a while now, and bigger ships have popped up, and different sightings have occured. The human scientists have been able to adapt to the alien technology with crashed ships and other specimens. Unfortunatley, the humans are running out of resources for the millions of people being made every day. The United Nations send out a ship capable of faster-than-light space travel. After about 5 years, a perfect planet is found with an environment similar to Earths. Contact has not been established with the aliens yet. The humans decide to show the aliens what they have found just in case they might get suspicious and turn out to be hostile. When the humans about 2 years later send out ships full of supplies, people, and other things to the planet, they find out the aliens are already there, and the aliens destroy the ships. The battle begins for the planet.