Kill 100 Brood Warriors
Kill the alien commander leading the resistance to the orbital assault.
Defeat the aliens in the jungle campaign.
Kill the Dominator Leader.
Complete the single player campaign.
Kill your first enemy in combat.
Kill the templar.
Finish the desert campaign on Extreme difficulty
Kill the last of the portal guardians and seize control of the portal to the alien home world.
Complete the first mission of the campaign.