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.
Concatenate multiple stealth kills
Use an explosive light to kill a guard
Obtain all 'Oni' medals
Perform a Ceiling Kill
Perform an aerial kill from a 10m height
Obtain all 'Yurei' medals
Obtain all 'Kami' medals
Complete Chapter 13
Complete Chapter 12
Unlock all Skills
Find all Scrolls
Summon 100 shadows
Complete Chapter 11
Get killed by an arrow while throwing a 'Kunai'
Complete Chapter 10
Complete Chapter 9
Complete Chapter 8
Obtain a 'Kami' medal
Complete Chapter 7
Complete Chapter 6
Completer Chapter 5
Make a guard suspicious 3 times in a row
Use 'Shinen' to swallow 3 guards at the same time
Die. Again. And again.
Obtain a ‘Yurei’ medal
Perform your first Shadow Kill
Complete Chapter 4
Kill 100 enemies
Destroy a Light Orb
Complete Chapter 3
Obtain a 'Oni' medal
Die while performing a stealth kill
Perform a Ledge Kill
Complete Chapter 2
Perform 100 Shadow Leaps
Skip a cinematic
Unlock a Skill
Find a Scroll
Complete Chapter 1
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'
Kill two enemies at once with the help of Twin Shadow (Single Player)
Obtain all 'Yurei' medals in 'Nightfall'
Complete Nightfall: Chapter IV
Obtain all 'Kami' medals in 'Nightfall'
Recover all Nisshoku Daggers
Complete Nightfall: Chapter III
Complete Nightfall: Chapter II
Complete Nightfall: Chapter I