Here is the full list of all 104 I Shall Remain achievements.
Finish the story on Normal difficulty (Hardcore)
Finish the game with "Chieftain" perk
Finish the game without using any unique weapon
Kill De Rossi
Kill Halfing Aberration
Kill Bunny
Kill Kramer
Kill Mantis Aberration
Kill Crawler Aberration
Kill Hetzenauer
Use mechanical actions 100 times
Kill Geronimo
Reach level 30 with main character
Kill Guardian
Kill Big Brother
Kill Monk
Unlock C.J.'s second ability
Kill Child
Unlock Jim's second ability
Read 30 books
Kill Martha
Kill Freddy
Use mechanical actions 50 times
Kill Renan
Recruit C.J.
Kill 500 elite infected
Plant 100 mines
Kill Hunterlag
Kill Krass
Throw 100 grenades
Kill Vilebyrd
Recruit Jim
Unlock Thomas's second ability
Reach level 20 with main character
Kill Newborn
Kill Wilson
Unlock Cathy's second ability
Kill Reaper
Kill Realdead Man
Recruit Thomas
Use medical actions 100 times
Kill Strider
Kill Lisard
Plant 50 mines
Read 20 books
Throw 50 grenades
Kill Carrie
Kill Ghunter
Unlock Patrick's second ability
Kill 100 elite infected
Kill Linger
Recruit Cathy
Unlock Andrea's second ability
Use mechanical actions 10 times
Unlock Tommy's second ability
Meet Julia
Reach level 10 with main character
Repair the tank
Recruit Patrick
Kill Murthog
Use medical actions 50 times
Kill 50 elite infected
Kill 1000 infected
Read 10 books
Recruit Andrea
Kill Infant
Recruit Tommy
Meet Dr. Andre Gratia
Kill Coloth
Throw 10 grenades
Plant 10 mines
Kill 500 infected
Kill 10 elite infected
Kill Beizel
Use medical actions 10 times
Kill 200 infected
Finish Prologue
Find Michael, your brother
Read one book
Kill Gobber
Kill 100 infected
Kill one Infected
Reach level 40 with main character
Kill 5000 infected
Use medical actions 500 times
Use mechanical actions 500 times
Throw 500 grenades
Plant 500 mines
Finish the story on Easy difficulty
Finish the story on Normal difficulty
Finish the story on Hard difficulty
Finish the story on Impossible difficulty
Finish the story on Easy difficulty (Hardcore)
Finish the story on Hard difficulty (Hardcore)
Finish the story on Impossible difficulty (Hardcore)
Finish the game with "Civilian" perk
Finish the game with "Athlete" perk
Finish the game with "Fighter" perk
Finish the game with "Detective" perk
Finish the game with "Policeman" perk
Finish the game with "Trooper" perk
Finish the game with "Agent" perk
Finish the game with "Sapper" perk
Finish the game with "Survivalist" perk