Here is the full list of all 28 Metal: Hellsinger achievements. It takes around 5-6 hours to unlock all of the achievements on Windows.
Soared (Dash + jump) 100 times
Killed a Judge's Aspect with Terminus
Died in a Chaos Crystal explosion
Destroyed the Red Judge
Destroyed the Red Judge aspect in Acheron
Killed 50 Behemoths
Destroyed the Red Judge aspect in Nihil
Destroyed the Red Judge aspect in Gehenna
Destroyed the Red Judge aspect in Incaustis
Obtained all weapons
Got 666 kills (game total)
Destroyed the Red Judge aspect in Yhelm
Completed a Torment
Achieved the top result in a Torment
Destroyed the Red Judge aspect in Stygia
Cleared a Hell using only Paz
Reached Hit Streak: 50
Killed 8 enemies in 4 seconds
Destroyed the Red Judge aspect in Voke
Reached Hit Streak: 35
Multi-killed 2 enemies
Reached Hit Streak: 20
Reached Hit Streak: 10
Completed all Torments
Never hit off-beat in a Hell
Died 20 times
Killed 25 enemies while maintaining a Hit Streak
Killed two Seraphs in one attack