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.
Find the second princess.
Meet with Yorick.
Find the first princess.
Resist temptation.
Put together the scroll.
Restore the banner.
Get all the answers.
Make yourself useful.
Save the refugees.
Become a true hero.
Defeat Laziness.
Persuade the King of Bards.
Tell a story that nobody's heard before.
Everyone needs to try it.
Survive the Innkeeper's attack.
Merge roads for the first time.
Take the scroll.
Sit on the Responsibility Stool.