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