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