Full list of all 26 Alekhine's Gun achievements worth 1,000 gamerscore. It takes around 12-15 hours to unlock all of the achievements on Xbox One.
Complete game without killing (except for assassination targets)
Use Chloroform on 30 enemies
Garrote 30 enemies
Hide 30 bodies
Level 11 Completed
Complete a level using one disguise or less
Level 10 Completed
Level 9 Completed
Obtain all disguises in the game
Level 8 Completed
Level 7 Completed
Perform a perfect rewiring (sabotage minigame)
Level 6 Completed
Get 30 Headshots
Level 5 Completed
Perfect lockpicking attempt
Level 4 Completed
Level 3 Completed
Level 2 Completed
Obtain Maniac Ranking on a level
Level 1 Completed
Complete all assassinations in a level using only accidents
Complete a Level without Killing (except for assassination targets)
Obtain Ghost Ranking on a level
Complete a level without using instinct mode
Complete a level without using your gun