Here is the full list of all 15 Noctropolis achievements.
Become the new Darksheer
Team up with Stiletto
Defeat the Succubus
Befriend Father Desmond
Reach Noctropolis
Shut down Greenthumb's greenhouse
Survive the assault of Tophat
Kill Master Macabre
Escape the Drealmer's dream world
Escape Master Macabre's maze
Discover the Whisperman
Defeat the arch-villain
Find the Bornick Mansion
Find Dynatek and Incarnate's ruins
Find the Neon Noose