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