Complete the indicated task to unlock the achievement.

Achievement	How to unlock
Aetriden Medal of Honor	The most highest ranked award is given. Most distinguished, exceptional, service tasks and missions are required for this medal. (combat)
Aetriden's Cross	For outstanding services you got a medal. (combat)
Bronze star	Awarded for completing various tasks and missions. (combat)
Call down the thunder!	You have taken out hellspawn with SHIVA weapon.
Campaign Order	Awarded to those that have managed to complete every mission in entire game on normal mode. (common)
Colonial Distinguished Service	Completing missions&continuously proving your service while confronted w/life threatening situations&saving others. (support)
Colonial Superior Service	Awarded for completing missions and continuously proving your service in the field while confronted with heavy assault and surviving. (support)
Commander Cross	Leaders who have distinguished themselves more then once in leading their squad to safety and avoiding almost death situations. (common)
Cross of Honor	Awarded for exceptional tasks and missions while distinguishing himself on battlefield. (combat)
Dirty Little Secret	You have completed the Insurgents storyline succesfully.
Distinguished Force Specialist	Awarded for continuously overcoming high number of test subjects with limited amount of supplies. (support)
Field Service Achievement	Awarded for completing missions and proving your service in the field. (support)
Field Service Commendation	Awarded for completing missions and continuously proving your service in the field. (support)
First encounter!	You have seen it, and you have killed it!
Force Specialist Cross	For outstanding services you got a medal. (combat)
Force cross	Awarded for completing various tasks and missions. Soldier must distinguish himself on battle. (combat)
Frosty	You have succesfully activted the distress signal with Frosty!
Legion of Assault	Continuously managed to complete random assault, defense and escape missions without taking any or minimal casualties to their squad. (combat)
Legion of Merit	Awarded for completing tasks and caring of others while surviving heavy situations on the field and saving others. (support)
Man of Duty	You have contributed to salvation of Tharsis, wheter for the good of it, or for the bad.
Nemesis of the dark	You got on the field, you took them down in one round, 50 high threat kills.
Order of Colonial Defense	Awarded to limited size squads that have exceptional performance on battlefield and have distinguished themselves in overcoming every incoming threat. (combat)
Order of Colonial Force	Awarded to those that have managed to continuously complete every mission given to them over many battlefield. (combat)
Project Terra	You have completed the Project Terra storyline succesfully.
Purple Heart	Awarded for suffering and recovering from life threatening wounds in combat. (common)
Silver star	Awarded for completing various tasks and missions without failure. (combat)
Soldier's Medal	This medal is given to those recruits that show great skills in the begining of their traning of ultimate survival. (common)
Survivalist	You have survived, and that's what it counts for!
Tactical Advantage	You have mastered all 8 classes.
Veteran's Medal	For outstanding services you got a medal. (common)
Veteran	You know your way around, you've been here for some time.
[M.E.R.C.S.]	Win the game in Hardcore, Primary, Secondary missions with 4 marines, and finish all objectives. Defeat Vivian Parks.