Here is the full list of all 19 Acting Lessons achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Chose Melissa's path
Completed Episode 8
Completed Episode 7
Completed Episode 6
Completed Episode 5
Completed Episode 4
Completed Episode 3
Completed Episode 2
Completed Episode 1
Unlocked all gallery scenes
Chose Ana's path
You are a matchmaker
Chose Rena as a partner
You spared Peter's life
Its fleece was white as snow
A new beginning for Liam
Chose Megan's path
You finished Peter
100!