Here is the full list of all 25 The Will of Arthur Flabbington achievements.
Start Act 1
Start Act 2
Start Act 3
Get the treasure!
Kill 10 flies
Read the How To Play section
Eat 10 donuts in one single game
Take 1000 steps with Jack
Take 21097 steps with Jack
Read one epitaph
Read all epitaphs
See one portrait
See all portraits
Bring flowers to one grave
Bring flowers to 10 graves
Ruin a love story
Request all songs
Reach 30 points in Farty Party
Make a "prosciutto e funghi" pizza
Make a "diavola" pizza
Make a "parmigiana" pizza
Make a "bomba" pizza
Get rejected as Kimberly
Try an exorcism
Lower the music volume in the settings in front of the metalhead kids