Here is the full list of all 20 Adventure of a Lifetime achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Start the game.
Watch the opening movie.
Watch the ending movie.
Open the gallery.
Open the config screen.
Open the sound screen.
Open the tips screen.
First tip is displayed.
Reach the end of the prologue.
Finish the common route.
Play to the end of the game.
Complete Emily's route.
Complete Chisa's route.
Complete all routes.
View your first event CG.
View 20% of all event CG.
View 40% of all event CG.
View 60% of all event CG.
View 80% of all event CG.
View 100% of all event CG.