The game's save system is bugged. It's recommended to complete the game without using it.
Walkthrough
Start a new game.
Take the flashlight and leave the room. Follow the arrow:
Inside the maze, take the right path and step through the small passage:
Open the door and go through the yellow steam:
Enter the prison, go straight forward and choose the middle door:
Leave this area and follow the trail through the forest:
Turn right and push the button:
Walk downstairs and enter the chamber of secrets:
Turn around and continue your journey.
Inside the house, open the second door on your right and step into the room:
Continue walking straight forward and walk right on the wall.
Head to the chapel and enter it:
Interact with the stone coffin to complete the game:
Achievement: Useless Way
Instead of walking along the small passage after the maze, go left until you reach a dead end:
Achievements: Secret Place & Message
Note: You have to pass a small parkour to reach the secret place. You can save at any time, but loading only works if you don't close the game after saving. However, you will lose the flashlight.
Back inside the prison, go through the right door and save in front of the abyss:
Jump on the small ledges:
Jump over two more traps:
Save in front of the stone barricade.
Instead of trying to reach the door, turn around and press "F" to move the wall:
Don't save here anymore!
Make your way to the last platform and jump into the secret room:
Go back, and jump off the last platform while it is lowered. Try to land below the secret room.
