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