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