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