Here is the full list of all 18 Message Quest achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Become a true hero.
Find the second princess.
Get all the answers.
Resist temptation.
Survive the Innkeeper's attack.
Restore the banner.
Meet with Yorick.
Find the first princess.
Merge roads for the first time.
Everyone needs to try it.
Persuade the King of Bards.
Tell a story that nobody's heard before.
Put together the scroll.
Take the scroll.
Make yourself useful.
Defeat Laziness.
Save the refugees.
Sit on the Responsibility Stool.