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