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