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