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 corn field.
Find the old outpost by the river.
Find the grave of the Fallen.
Explore the maze.
Magic under the Roar.
Cross the wooden bridge.
Visit the railroad and the train wreck.
Find the hidden passage.
Visit the ruins.
Find the Gorge.
Explore the tombstones.
Remember her neck tattoo.
Red tree inside the Pit?
Walk under the waterfall.
Explore the Graveyard.
Explore the mine that goes on top of the mountain.
Explore the boats by the shore.
Visit the Tower.
Explore the Radio Station.
Explore the wooden windmills.
Explore the wrecked coal mine.
Swords and Skulls.
Explore the Church.
Wake up on the Island.