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