Here is the full list of all 29 Marlow Briggs and the Mask of Death achievements.
Watch all credits
Complete the game on any difficulty
Defeat HellHound
Kill enemy with each magic
Defeat the Air boss
Fly across the chasm
Kill enemy with each weapon
Solve the temple puzzle
Defeat the Water boss
Gain entry to treasure room.
Perform a 50-hit combo
Solve the water puzzle
Launch enemy and kill it before it falls on ground
Survive train-cart ride
Kill enemy with air combo.
Find a collectible
Execute an enemy
Destroy 10 enemies using only spirit knives
Defeat the Fire boss
Kill enemy with enviromental objects (fire, barrel,...)
Earn upgrade point and spend it
Kill enemy with deflected projectile
Knock enemy off ledge into their falling death
Get your first achievement
Block enemy attack.
Complete the game on Hardcore difficulty
Glide for more than 6 seconds
Skip all cutscenes in one play through
Find all collectibles in one play through