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