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