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