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