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 Graveyard.
Walk under the waterfall.
Swords and Skulls.
Explore the corn field.
Explore the wrecked coal mine.
Visit the ruins.
Find the old outpost by the river.
Red tree inside the Pit?
Explore the wooden windmills.
Find the grave of the Fallen.
Explore the maze.
Find the Gorge.
Remember her neck tattoo.
Find the hidden passage.
Explore the Radio Station.
Explore the mine that goes on top of the mountain.
Explore the boats by the shore.
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.