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