Here is the full list of all 17 Super Mutant Alien Assault trophies - there are 13 bronze and 4 silver.
Defeat a boss in under 10 seconds.
Unlock all equipment.
Keep a booooomerang in the air for 30 seconds.
Kill 6 enemies with one sniper bullet.
Use your pulse belt on a cooking explosive.
Kill the galaxy 3 boss.
Kill the galaxy 2 boss.
Make a gas ball travel at high speed.
Kill the galaxy 1 boss.
Wipe out an entire monarch flock with one sniper bullet.
Beat the game in one run on normal difficulty, by yourself.
Beat the game in one run on heroic difficulty, by yourself.
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.
Activate 30 pressure machines with explosives.