Here is the full list of all 15 Siebenstreich's Nerdventure achievements.
Seal Mirrormore's doom.
Save Mirrormore.
Kill your hero.
Save Mirrormore without dying.
Provoke Henry into commenting a failed crafting attempt.
Provoke the GM into destroying your wooden spoon.
Complete the Sylvan Knowledge challenge without error.
Complete the A Game for a Throne challenge without error.
Finish the stew challenge without time penalty.
Beat the flies on the first attempt and without flaw.
Create the cereal without harming your hero.
Successfully finish the game in 42 minutes or less.