Here is the full list of all 17 Chained Echoes Demo achievements.
Play the game during gamescom.
Find all notes.
Open all treasure chests.
Buy every Deal.
Get all characters.
Get all weapons.
Defeat Tak the Yak.
Defeat the Shashlik.
Beat the demo.
Keep playing after finishing the demo.
Pay the kid in Basil for the same information twice.
Defeat the weapon dealer.
Defeat the Slorse 5 times.
Use the mushroom during the final battle.
Scare 10 birds away.
You read correctly.
Find the married fish couple.