Here is the full list of all 33 Thimbleweed Park achievements.
Didn't pick up any specks of dust.
Complete the game in casual mode.
Pushed the circus mime over.
Collected 75 specks of dust.
Grew Leonard's plant to superhuman size.
Stayed for all the credits.
Complete the game in hard mode.
Got Ransome's bad ending.
Part Nine: The Deleting.
Part Eight: The Escape.
Navigated to the buried treasure.
Used Ransome's Itch Cream.
Blew up the Mansion.
Part Seven: The Madness.
Part Six: The Factory.
Begin Part Five.
Get an alive character into the Hotel penthouse.
Begin Part Four.
Catch the killer.
Collect 50 specks of dust.
Make everyone cry about their life.
Listen to 100 Voicemail messages.
Read 100 books in the library.
Read all the Thimbleweed Nickel newspapers.
Visited every floor in the hotel.
Collect 25 specks of dust.
Complete Franklin's Flashback.
Begin Part Three.
Complete Delores's Flashback.
Escape from the sewers.
Complete Ransome's Flashback.
Begin Part Two.
Begin Part One.