Here is the full list of all 18 Blackwell Epiphany achievements.
Somebody's got to do it...
Try to lie your way out of it
Finish the game in commentary mode (from the first screen till the last)
Learn a long kept secret
Blow on everyone you can find
Find a secret room
Create no more than 450 footprints
Complete the story
Free yourself
The hows and whys of Joey
Reunite a family
Two becomes one
Make a leap without falling once
Keep clam and keep cool
She has plenty of time...
Save your first ghost
Gain access to an online game
Solve a puzzle together