Here is the full list of all 29 Dark Nights achievements.
Death end 1
Peaceful passing
Written by the author
Are you curious about his brother?
Junoru's romantic ending
Death end 2
Mask it off
Such an aggressive MC
The opening theme piano version
Kurato's normal end
Death end 8
Going for both, I see
The bed is safe, right?
Kurato's romantic end
He is coming
Death end 7
Zeikun's normal ending
Not that easy
Zeikun's romantic ending
Death end 4
Reward for studying well
Good job guessing!
Death end 3
Sachiro's normal ending
Sachiro's romantic ending
Holy umbrellas
Death end 6
This is a horror VN
Not the usual choice