Here is the full list of all 92 Project Aftermath achievements.
Take over a walker
Complete the Tutorial
Resurrect a hero
Put your account online
Get all 4 Heroes above Power 10
Earn 6 Medals
Earn 10 Medals
Earn 10 Gold Medals
Complete all Missions without the use of Troopers
Use all weapons at least once
Use all Field Effects at least once
Use all Augmentations at least once
Drop 50 Enemies into Chasms
Kill 100 enemies using the 'Traitor' Field Effect
Kill 1000 enemies
Kill 2000 enemies
Kill 10000 enemies
Kill 200 enemies using the Chain Sword.
Kill 200 enemies using the Lightning Gun
Kill 200 enemies using the Cerebral Hammer
Kill 20 monsters using the Gene Ripper
Kill 20 walkers using the Ion Beam
Kill 50 enemies under the influence of the Shroud of Darkness
Kill 50 enemies under the influence of the Speed Suppressor
Take over 20 Walkers
Collect 50 pickups
Heal 100 units
Resurrect 40 troopers
Get one of your Heroes to Power 10
Complete a mission while 10% under equipping budget
Complete a mission while 30% under equipping budget
Complete a mission while 50% under equipping budget
Complete a mission without regenerating health or resurrections
Complete a mission using only Melee weapons
Complete a mission using only Ranged weapons
Complete Mission 1 without Tactical Deployment or Field Effects
Complete Mission 2 without Tactical Deployment or Field Effects
Complete Mission 3 without Tactical Deployment or Field Effects
Complete Mission 4 without Tactical Deployment or Field Effects
Complete Mission 5 without Tactical Deployment or Field Effects
Complete Mission 6 without Tactical Deployment or Field Effects
Complete Mission 7 without Tactical Deployment or Field Effects
Complete Mission 8 without Tactical Deployment or Field Effects
Complete Mission 9 without Tactical Deployment or Field Effects
Complete Mission 10 without Tactical Deployment or Field Effects
Complete Mission 1 in under 15 mins
Complete Mission 2 in under 12 mins
Complete Mission 3 in under 12 mins
Complete Mission 4 in under 12 mins
Complete Mission 5 in under 15 mins
Complete Mission 6 in under 15 mins
Complete Mission 7 in under 15 mins
Complete Mission 8 in under 15 mins
Complete Mission 9 in under 15 mins
Complete Mission 10 in under 15 mins
Complete all Challenge maps in normal mode
Complete all challenge maps in extreme mode
Complete Staying Alive in normal mode
Complete Finders Keepers in normal mode
Complete Hitman in normal mode
Complete None Shall Pass in normal mode
Complete Death From Above in normal mode
Complete All Mixed Up in normal mode
Complete Safe Passage in normal mode
Complete Surrounded in normal mode
Complete The Bridge is Mine in normal mode
Complete The Shepherd in normal mode
Complete Staying Alive in extreme mode
Complete Finders Keepers in extreme mode
Complete Hitman in extreme mode
Complete None Shall Pass in extreme mode
Complete Death From Above in extreme mode
Complete All Mixed Up in extreme mode
Complete Safe Passage in extreme mode
Complete Surrounded in extreme mode
Complete The Bridge is Mine in extreme mode
Complete The Shepherd in extreme mode
Research all Items
Research all Physical Weapons
Research all Biological Weapons
Research all Energy Weapons
Research all Field Effect Weapons
Research all Field Effects
Collect all pickups
Destroy the Genetics plant in 'Unfinished Business' and exit with the engineer.
Kill a Walker with another Walker
Kill 200 grunts in a single mission
Kill 100 enemies without losing a man
Kill 10 enemies in 5 seconds
Kill 25 enemies in 5 seconds
Collect all Data-cores
Kill 200 enemies using the Tactical Plague Gun