Here is the full list of all 20 Onirike achievements.
Free the clown from the puppet's strings
Unveil the secret of the stone heart
Open the bamboo door
Open the door of the ribs door
Collect 100 gypsophila petals
Collect all the gypsophila petals of the orb
Collect 20 gypsophila spores in a single day
Plant 100 gypsophila flowers
Light the Sea of Doubt Lighthouse
Empty the Sea of Doubt
Cross the chessboard with 5 knight moves
Get the cardboard village train going
Cross over to the other side of the magic doors
Complete the pizza of the Putrid Zone
Get the eye of the wolf
Reach the top of the great volcano
Make smoke come out of your head
Gather the 7 fragments of the key to the Well of Truth
Use the power of illusion 20 times
Open the Well of Truth