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