Different worlds have the same problems. Pollution, wars, diseases, lack of natural resources. Different worlds have the same solutions. Kill, conquer, dominate.
Your planet has been attacked by aliens and its time for you to show some action and get back your planet.. Destroy all the aliens, Get weapon upgrades and take back what is yours.
The planet earth is under attack. Fortunately, we have these advance battle suit to fight back. Engage and destroy incoming alien transports and shutdown their mothership.
After a successful teleport our hero ends up on the basement level of AS7 medical research facilty. He finds new challenges and evidence of resistance, but still no survivors, the only ones alive are the undead.