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