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.
Destroyed the Red Judge
Killed 50 Behemoths
Destroyed the Red Judge aspect in Acheron
Soared (Dash + jump) 100 times
Destroyed the Red Judge aspect in Nihil
Destroyed the Red Judge aspect in Gehenna
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: 20
Destroyed the Red Judge aspect in Voke
Died in a Chaos Crystal explosion
Multi-killed 2 enemies
Reached Hit Streak: 10
Reached Hit Streak: 35
Reached Hit Streak: 50
Completed a Torment
Achieved the top result in a Torment
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
Killed 8 enemies in 4 seconds
Cleared a Hell using only Paz
Killed a Judge's Aspect with Terminus