Here is the full list of all 24 Oracle achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Red tree inside the Pit?
Walk under the waterfall.
Explore the Graveyard.
Swords and Skulls.
Explore the wooden windmills.
Explore the corn field.
Explore the wrecked coal mine.
Visit the ruins.
Find the old outpost by the river.
Find the grave of the Fallen.
Explore the maze.
Find the Gorge.
Explore the mine that goes on top of the mountain.
Explore the boats by the shore.
Visit the Tower.
Remember her neck tattoo.
Explore the Radio Station.
Find the hidden passage.
Magic under the Roar.
Visit the railroad and the train wreck.
Cross the wooden bridge.
Explore the Church.
Explore the tombstones.
Wake up on the Island.