Here is the full list of all 50 Ace Combat: Assault Horizon (GFWL) achievements worth 1,000 gamerscore.
Obtained an A rank for every mission (free mission).
Cleared all levels in mission co-op.
Joined the same DFM with two others and shot down a hostile (mission co-op).
Cleared 1 level in mission co-op.
Sortied for 50 hours in competitive online or mission co-op.
Piloted all aircraft in the game.
Used Trinity to wipe out the enemy (free mission).
Destroyed all radar missile defense systems in a short period of time.
Defeated a large number of enemies while flying a bomber.
Took down 5 hostiles in a row with an assault chain.
Flew through the big hotel's gates.
Successfully pursued 3 enemies with counter maneuvers.
Cleared all missions.
Protected Washington D.C. from the threat of Trinity, and returned alive.
Pursued the enemy and shot down Major Illich.
Alleviated the attack on Miami and helped Guts bail out.
Took down 3 hostiles in a row with an assault chain.
Protected Moscow from destruction, freeing it from enemy control.
Destroyed the air defense system, opening the way for allied pilots.
Destroyed the ICBMs.
Sank the enemy fleet and saved the Russian Prime Minister.
Managed to get Sova 1 to land safely.
Successfully took off to protect allies amid heavy hostile fire.
Prevented enemy from using Trinity to destroy Derbent.
Successfully focused on 3 targets.
Wiped out hostile ground forces with ASM.
Eliminated enemy threat from the Suez Canal.
Disintegrated enemy bombers in mid-air, keeping damage to the city to a minimum.
Attempted an emergency landing in a damaged aircraft.
Successfully switched from defense to offense 10 times with counter maneuvers.
Protected your allies using the gunship, and led a successful attack on the base.
Defeated hostiles with all 3 of the gunship's weapons.
Rescued Major Illich from enemy captivity.
Obtained and destroyed 10 enemies in a helicopter.
Removed enemy presence from the oil field and the base.
Flew beneath a falling chimney.
Took down 5 hostiles with a direct shot.
Took out a large number of hostiles as the door gunner.
Destroyed 5 hostile vehicles from the air as the door gunner.
Ejected from a damaged aircraft.
Played on all maps in competitive online.
Shot down a large number of hostile players in competitive online.
Destroyed an enemy aircraft using only the standard machine gun while piloting an aircraft.
Used DFM to destroy 10 airborne enemies in competitive online.
Obtained all MVPs.
Saved an ally being targeted by hostile players in DFM in competitive online.
Took down a hostile fighter with a charged homing missile.
Used ASM to destroy 30 ground enemies in competitive online.
Used DFM support or ASM support to join a flight member.
Used an attack helicopter and destroyed 10 missiles or bombs in competitive online.