Here is the full list of all 9 Bubble Ghost Remake Demo achievements.
Complete the game's demo
Complete the demo without letting the bubble pop
Leave the mother bat behind without sacrificing your bubble
Make Heinrich fall asleep
Complete the demo in less than 20 minutes
Follow the path of the magical rings and ensure you have them all
Find all hidden collectables throughout the levels
Uncover the secret ring
Unlock all secrets this demo has to offer