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