Here is the full list of all 24 Cleo - a pirate's tale achievements. It takes around 5-6 hours to unlock all of the achievements on Windows.
Win all Kraken Fodder games on the first try
Complete the Coffee to Know Meditation flawlessly
Win against Fleur on the very first try
Do not dare to go into the dark
Pick all Folo flowers on the island
Bring exactly 20 flowers to the siren
Don't give up until you win your first round of Kraken Fodder
Solve the finger puzzle in just two steps
Try to take a fish after Herbert left
Thank you for playing "Cleo - a pirate's tale"!
Suffer more than 20 electric shocks
Play Cabeca's leitmotif on the kalimba
Cut off all tufts of grass
Defeat Erik, Fleur and Schmodor in Kraken Fodder
Fall down the stairs of the lighthouse twice
Find all 64 messages in bottles
Visit every place of the McIanlly Palms map
Read 25 different messages in a bottle
Go fishing 100 times
Read 10 different messages in a bottle
Go fishing 50 times
Read a messages in a bottle
Go fishing 25 times
Win your very first game of Kraken Fodder