Your beacons are under attack by the alien insects. Your mission as an elite commando is to defend your beacons from being destroyed by those monsters. As you progress through the game, you will be able to get several upgrades for your weapons and abilities. Use them wisely so that you are able to fight those monstrous aliens. Watch out for your health bar. Switch between firing modes using the numeric 1-4 keys and use the WASD keys to move around. Use the mouse to aim and shoot towards the enemy. Fire grenades and kill whatever that comes in your way.