Full list of all 51 Aragami achievements. It takes around 15-20 hours to unlock all of the achievements in the base game on Windows.
The base game contains 39 achievements, and there is 1 DLC pack containing 12 achievements.
Unlock all Skills
Find all Scrolls
Obtain all 'Oni' medals
Obtain all 'Yurei' medals
Complete Chapter 13
Obtain all 'Kami' medals
Complete Chapter 12
Complete Chapter 11
Use an explosive light to kill a guard
Perform a Ceiling Kill
Perform an aerial kill from a 10m height
Get killed by an arrow while throwing a 'Kunai'
Use 'Shinen' to swallow 3 guards at the same time
Perform a Ledge Kill
Make a guard suspicious 3 times in a row
Complete Chapter 10
Complete Chapter 9
Complete Chapter 8
Complete Chapter 7
Complete Chapter 6
Completer Chapter 5
Die. Again. And again.
Perform your first Shadow Kill
Complete Chapter 4
Unlock a Skill
Destroy a Light Orb
Complete Chapter 3
Obtain a 'Kami' medal
Summon 100 shadows
Kill 100 enemies
Die while performing a stealth kill
Complete Chapter 2
Perform 100 Shadow Leaps
Concatenate multiple stealth kills
Find a Scroll
Skip a cinematic
Complete Chapter 1
Obtain a ‘Yurei’ medal
Obtain a 'Oni' medal
Kill 4 or more enemies at once with the Explosive Kunai
Blind 4 or more enemies with a Shadow Grenade
Obtain all 'Oni' medals in 'Nightfall'
Complete Nightfall: Chapter IV
Obtain all 'Yurei' medals in 'Nightfall'
Obtain all 'Kami' medals in 'Nightfall'
Recover all Nisshoku Daggers
Complete Nightfall: Chapter III
Complete Nightfall: Chapter II
Complete Nightfall: Chapter I
Kill two enemies at once with the help of Twin Shadow (Single Player)