Here is the full list of all 12 HAWKEN achievements worth 1,000 gamerscore. It takes around 4-5 hours to unlock all of the achievements on Xbox One.
Eliminated 100 enemy mechs while they were repairing.
Eliminated an enemy mech that was zoomed in while you were also zoomed in.
Eliminated an enemy mech that was currently zoomed in.
Eliminated 10 enemy mechs while they were repairing.
Dealt over 10,000 damage to yourself with your own explosive weapons.
Survived over 15 seconds with less than 10% armor, and then eliminated an enemy mech.
Eliminated an enemy mech while it was repairing.
Eliminated an enemy mech by landing on it, crushing its robot soul.
Eliminated an enemy while it was under the effect of your EMP.
Eliminated 10 enemies without dying.
Eliminated an enemy mech while its weapons were overheated.
Completed the final stage of VR Training and received your Basic Training Certification.