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