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 Eight.
Make your decision.
Complete Chapter Seven.
Complete Chapter Six.
Complete Chapter Five.
Collect all elementals.
Persuade the spirit of air to help you straight away.
Give all items to Xerxes.
Complete Chapter Four.
Ashes to ashes, stone to dust.
Complete Chapter Three.
Defeat the spider.
The forest is my home.
Find the fox within the labyrinth.
Complete Chapter Two.
Catch the rabbit at the first try.
Shards crack loudly.
Give Bryda the wrong astral accumulator.
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.
Do you have the guts to start an argument?
Tread lightly.
Stone, dust, stone, dust.
Throw all items into the chasm.
Adjust the horns towards the spheres.
Find the Caverns of Fail.