:THE LONGING:

The Halls of Eternity

Enter the Halls of Eternity, the path to get there is shown below:

Mattock

Pick up a Mattock (pickaxe). There are a total of four in the game:

• one in the Mine shaft
• one is above the white crystal room
• one close to the person that wanted to be an unicorn close to the secret tower
• one close to the place you see in your Dreams

Head of a Horse

The head of a horse can be found in the Halls of Eternity, it took me 30 minutes of walking to find it however that may be different for you as it is randomized as to when it will appear.

Running Water

Roll the rock out of the way so that the water runs, map to the rock below:

Once the rock is moved and the water is running, return to the Shades home to find your new sink.

Dream

Stand still for long enough that the Shade falls asleep, he will dream and the achievement will pop. Alternitively you can eat three purple mushrooms to cause the Shade to pass out and dream as well.

Home Improvement

Use your mattock to expand the Shades home, the achievement will pop when there is nothing left to dig in the home area. The last thing you should find when digging is a pool of water. This is a prerequisite for the "Bed" achievement.

Colorful Stones

Find all 5 colors to draw paint with. This achievement is a prerequisite for the "My Favourite Painting" achievement.

• Coal (black) can be found pretty much everywhere, so this is the easiest one to find.
• Clay (red) can be found randomly on the ground in the caves.
• Lapis Lazuli (blue) can be found randomly on the ground in the caves.
• Chalk (white) can be found randomly on the ground in the caves.
• Sulfur (yellow) can be mined in the sulfur mine, and will take awhile before you can get to this location, the path to get there is below:
  

My Favourite Painting

Draw the Louse painting in all 5 colors.

Disappointing Achievement

Obtain 5 disappointments, these can be gained by either failing tasks such as not being able to jump up ledges or by walking to dead ends (such as the blocked door to the library). There are a total of 12 disappointments throughout the game, and they are fairly easily found. Here is a map of the ones I have found and know about, its not complete but enough for the achivement:

The Library

Enter the library. You'll need to wait for 30 in-game days before this becomes available, as a pool of water needs to fill up. The path is below, and circled in red is the pool of water:

Secret Tower

Find the secret tower. This achievement is a prerequisite for the "Neverending Notebook" achievement. Go through the darkness area near the surface, while walking in the dark you will find an area where your footsteps change from walking on stone to walking on dirt. Once this happens change directions and walk up and to the right. This will lead you up a staircase and follow the path to the tower.

Neverending Notebook

Find the Neverending Notebook in the secret tower and add enough text to the [...]\Steam\steamapps\common\The Longing\The Longing_Data\StreamingAssets\books_plaintext\notebook.txt file located in the games directory so that it is longer than 2 pages in-game. You will need to restart the game after adding text to this file.

This is the only official way to get this achievement, as stated by the developer of the game in the Steam forums:
https://steamcommunity.com/app/893850/discussions/0/1745647229713753045/#c1745647229714362849
https://steamcommunity.com/app/893850/discussions/0/2139714324747601972/#c2139714324757784336
https://steamcommunity.com/app/893850/discussions/0/1745647229713753045/#c1745647229715924264

This most likely needs a edge case rule added here, but hasn't been as of the time of writing:
https://achievementhunting.com/rules

Its probably fine, but use at your own risk I guess.

Bed

Build a bed in the basement of your home after expanding it. You will need 10 wood and 20 moss. The moss and wood can be collected in the caves, however to get enough wood for the bed you will need to make your way towards the surface, as only 9 can be found in the lower caves.

Becoming Darkness

Sit still for long enough that a dialogue with choices appear, choose until you find an option that says "Become the darkness". This is a prerequisite for the "Leaving Darkness" achievement and gives you the ability to close your eyes.

Leaving Darkness

When you encounter eyes in the darkness sit idle rather than walk towards them, once you do you will be given an option to close your eyes. Do so and walk past the eyes in the darkness, once you do the achievement will pop.

Home Sweet Home

Find furnature in the Halls of Eternity, have plenty of paintings, and build a nice fire. Make the Shades home nice and cozy, once you are moving at around 15 in-game seconds per IRL second the achievement will pop. Below is a screenshot of how the Shades home looked when I got this achievement:

Crystal Glory

Mine all 5 crystal types and place them in your home as decorations. You will need a mattock, so that makes the "Mattock" achievement a prerequisite for this.

• Pink crystal can be found in the caves near the surface.
• Dark crystal can be found in the caves near the Halls of Eternity.
• Blue crystal can be found in the cave with the face.
• Red crystal can be found in the central hall.
• White crystal can be found in the cave with a waterfall.
  

A Face

Talk to the face in the cave walls. You will need to wait for 7 days in-game in order for the path circled in red to become available. The face can be found here:

The Cave

Discover every location in the game. This is fairly easy if you get all of the other achievements, as you will need to travel through most, if not all, of them already. But if you are having trouble with this you can light a sulfur fire in the Shades home, which will cause him to walk to an undiscovered location.

Mushroom Gardener

Grow mushrooms in your home after digging out the basement. I didn't count, but various other guides have said you need to plant 8.

Avid Reader

Read a lot of books, you can do this while the game is closed to pass time quicker or just spam click through the pages to finish the book fast. This isn't based off of finishing books, but rather pages read, as I got the achievement half way through a book.

The Map

Stand in front of the map on the wall until the game zooms out enough for you to see the entire map. The room can be found here:

Wah Wah Wah Waaah

Once you find the four parts of the instrument you can play music in the Shades home, play music by moving your mouse around and right-clicking. Play a few notes and this achievement will pop.

Birthday

Play the game on the 365th in-game day (when there are 35 days left on the count down timer). This achievement is possible to miss if you don't have the game open when that day is happening.

The End of Longing

Finish the game through any of the 5 endings.