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