Here is the full list of all 30 The Dark Pictures Anthology: Man of Medan achievements.
Finished the Shared Story
Chose all of the Head decisions
Chose all of the Heart decisions
Maxed Conrad and Fliss's Relationship
Found all Secrets!
Found all Pictures
Unlocked Fliss's Arrogant Trait
Maxed Brad and Alex's Relationship
Only the women survived!
Found all of the black framed Pictures
Found all of the white framed Pictures
Conrad successfully escaped on the speedboat
Opened the window without making noise
Everybody survived!
Calmed Junior down
Only the men survived!
Finished Movie Night
Completed 10 QTEs in succession
Unlocked Julia's Spoilt Trait
Beat the Training Dummy
Conrad successfully flirted with Fliss
Unlocked Brad's Envious Trait
No-one survived!
Completed the Solo Story
Revealed the name of the ship
Found 25 Secrets!
Maxed Alex and Julia's Relationship
Unlocked Alex's Aggressive Trait
Unlocked Conrad's Humorous Trait
Julia accepted Alex's proposal