Here is the full list of all 31 The Dark Eye: Memoria achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Complete Chapter Three.
Defeat the spider.
Find the fox within the labyrinth.
Complete Chapter Two.
Catch the rabbit at the first try.
Give Bryda the wrong astral accumulator.
Shards crack loudly.
Do you have the guts to start an argument?
Turn the pig on the grill.
Does Bryda know who you really are?
Complete Chapter One.
Do You Like Riddles?
Try to tear down the wall with the golem.
Find out who of the adventuring party lies at the first try.
Tread lightly.
The forest is my home.
Ashes to ashes, stone to dust.
Stone, dust, stone, dust.
Complete Chapter Four.
Throw all items into the chasm.
Give all items to Xerxes.
Persuade the spirit of air to help you straight away.
Adjust the horns towards the spheres.
Collect all elementals.
Find the Caverns of Fail.
Complete Chapter Five.
Complete Chapter Six.
Complete Chapter Seven.
Make your decision.
Complete Chapter Eight.