Here is the full list of all 17 Super Mutant Alien Assault achievements worth 1,000 gamerscore.
Wiped out an entire monarch flock with one sniper bullet.
Beat the game in one run on heroic difficulty, by yourself.
Beat the game in one run on normal difficulty, by yourself.
Killed the galaxy 3 boss.
Killed the galaxy 2 boss.
Killed the galaxy 1 boss.
Beat the game in one run on epic difficulty, by yourself
Beat the game in one run on normal difficulty, with a partner.
Beat the game in one run on heroic difficulty, with a partner.
Beat the game in one run on epic difficulty, with a partner.
Defeat a boss in under 10 seconds.
Kill 6 enemies with one sniper bullet.
Make a gas ball travel at high speed.
Unlock all equipment.
Use your pulse belt on a cooking explosive.
Activate 30 pressure machines with explosives.
Keep a booooomerang in the air for 30 seconds.