40% of the achievements are easy to earn. The others require time and skill, or luck.

I will describe as clear as i can, but if there is a note you don't understand, leave a comment, i will try to explain it easier.

Gross, It's All Wet - Acquire the Soul of Dagon
Just finish the dark blue book. There is four worlds ,so three exit doors to open before reach the soul. In a world, each exit door is two level down.


Gross, It's All Sandy - Acquire the Soul of Nyarlathotep
Just finish the red book. There is four worlds ,so three exit doors to open before reach the soul. In a world, each exit door is two level down.


Gross, It's All Slimy - Acquire the Soul of Cthulhu
Just finish the green book. There is four worlds ,so three exit doors to open before reach the soul. In a world, each exit door is two level down. Be careful for this one, you need a key, dynamite or shot explosive to get this soul.


Well Read - Read the complete History of the Library
Basically, you have to read all four books about the history about the library, called themselves « The history of the library ». They are in the main hub, the library. Don't worry to find them, they are several copies of these books in the hub.


All That Junk - Deposit 9,999 artifacts in the bank chest
You can dot it by playing the game for hours to get artifact (money of the game) and remember, don't spend it in shop. Be sure to save the money in a bank chest, it's a deadly game.
It's very long, but the only way is farming monsters, worlds and rooms where a bank chest is.

Go find the locksmith to open all locked door (there is often artifacts behind them) and the lucky charm (to maximize the loot on an enemy's body).


Sweet Revenge
I launch a dynamite and boom, lizardman statue explode and i get the achievement.

These Timeless Words - Perform the Ritual of Binding
In one playthrough, you have to obtain the three souls (the blue, the red and the green). Put them near the exit door in the library (just right behind the world book actually). Be careful, all the monsters types are behind this door.
And again, it's four world, symbolized by three exit doors. But this time, you have to go up to find them, not go down.


Free at Last
In each book, there is a secret book and so a special item (holy item). As some comments introduced a mistake i wrote, these secret books could be found in the second world.
I think you should do the red and the green book first, because in the dark blue one, you loose the compass as the item replace it.
You don't need dynamite. There is always an entrance to the secret book (in my play). Still, if you use dynamite, you will need two slots as the wall is thick.

Once you collect all the items and the souls, go to the manor (or the endless library) and light up three candles, one per world.
Keep safe the dynamite to blow up an access for the candles. But as for the secret book, there is always a free entrance

If you do this, go to the last exit door and the achievement should appear.



As Fast Azathoth
When you are in the asylum (after read the orange-fire book), you have to go through a dark smoke and enter an area limited for 3 minutes. You can go to the next area or ... wait 3 minutes, but prepare to run. The game warn you that Azathoth will kill you if it catch you. You have to run during 3 minutes and you can earn the achievement.
A good thing is ennemies can't hurt you when you are running, at least 90% of the attack are missed. But keep trying to avoid them if it's possible.
A good strategy is to jump while you are running : your speed is increased twice.



R'lyeh Nice to Meet You
Read the light blue book and take the star-shaped artifact (soapstone) near the first exit door of this world. Now, continue until you reach the last world (the one with the altar). There is a secret book here which can make you go back to the library. For my case, this book was in a room without entrance and the only way to access it is to dig through the wall. So be sure (if this locked room is not random) to have a pickaxe (two knock is enough) or dynamite.
When you come back to the main hub, read the green book and talk to the starspawn shopkeeper, with the soapstone in your inventory.

Not a Scratch - Finish the game without taking any damage
The easiest way to earn this achievement (i don't say it's easy), except using bonus item, is running the game :
- On stealth mode
- Do not fight, or at least with range weapon
- On normal game, not in harder new game +
Some spells are useful like the one where you are superman or the other one where you were insivibleman.

If it can help you, there is a spell that give to you the ability to lift, to boost your jump. It cost 1 artifact per use, but if you take the conjurer's talisman, you can use the spell indefinitely. So you can dodge enemy's melee attack, but the projectiles are still a threat, even if it's hard to aim you.


A Marvel I Cannot Fathom - Finish the game in New Game+ mode
As the "Not a Scratch" achievement, i woul recommend same advices. The only difference, except the harder way, is at the beginning : you have to grap the white soul to choose the new game + mode.

Edit : i do it in 29 minutes and i don't loose a single life point, so i earn "Not a Scratch" as well. I was wearing the compass and the locksmith (i stole them from the shopkeeper in the first world of the dark blue book). And i often use stealth mode with some sprint. I also fired nearly thirty bullets.



What Final Horror - Escape the Mountains of Madness
First, take the compass from the dark blue book, then go back to the main hub (library). Then, you have to read the light blue book to enter a snowing area (the Mountain of Madness). Prepare for a long walk, because you have to go down to a level known as the Lost plateau of Leng. In this area, after ten exit door, you have to grab the keys from your plane at the center and ... go back to your plane, of course.
But the tricky part is about a fuc.... smoke (Shoggoth) which is stuck on your body. Congratulations, now you know how it feel to be a blind person. Except there are several monsters which want your blood.
Keep running (i remember Outlast), and if you're lucky (or if you have left enought fountain, meat and campfire), you can leave this nightmareland with your plane.
A useful combination is compass and pickaxe : go through the level until the exit symbol in on your feet and dig. But change the pickaxe when you can or it can be broken when you are in a hole too hight to escape it.



Soul Purpose - Free 500 trapped souls from the Asylum
Read the orange book to enter in the asylum. Here, after you pass through the first black smoke, you have to pass through this smoke three more times to end the asylum and keep safe the souls (white orb) you have collected.
The environment is more dangerous than the other book, except the ligth blue one.
You can keep an eye on your score souls in the first room of the asylum, on the leaderboards (on the right).
You have to collect 500 souls in one playthrough. There is a "soulstone" which increased the amount of souls.
Try to avoid enemy and take two pickaxe, because monsters can't kill you when you are running.

Three ways to obtain soul :
- Break the environment (white glowing or not, see the trick below) to get 10 souls
- Pick white orbs you can see to get 5 souls
- Use the spell called "soul trap". It cost 10 artifacts but you can transform enemy in 5 souls

The best equipments are :
- Spell "soul trap" (using it against enemy and it will become a soul)
- Jump Boot (you can reach most of the white orb)
- Soulstone (increase souls gain) or conjurer's talisman (reduce cost for spell - wonderful with "soul trap")
- Locksmith (you can get more artifacts to use your "soul trap" and all white orbs behind lock door)
- Pickaxe rather than dynamite : dynamite is a single use contrary to pickaxe for extract white orb.

I found a trick : When you see this type of rock alone in a wall, there is a soul behind. I earn the success in one try after discover that.




Never Enough Time - Finish the game in under 10 minutes
I do it in 12 minutes and i was stuck in a world, so it's more possible than you think. You need skill, but also big luck to find good items. Go find the compass in the dark blue world and go back to the library.

The order to respect :
- The red book. The red book is the hardest (especially with the statue lizard). So it's better to do first the most dangerous before the easier (and avoid to die after minutes of run). Keep a dynamite for the last world to destroy the surrounding wall, with the lizard statue path. Or you can stand on the first floor, reach the exit symbol on your feet, let the dynamite explode and boom, you grab the soul and go back to the library.
- The green book. Keep a key and a dynamite or two keys to get the soul at the end. Or use the same tactic as for the red book.
- The dark blue book. Just run.
- The manor. It's more difficult as you have to go up, so the dynamite is useless. And as you run for the books, you can't spend time to seek spell or special item like jump boots.

Here's some advices :
- It's obvious, but you have to run, always run.
- You can also jump while running to increase your speed, but be careful to the trap.
- If you spend more than 1 minute in a world, resurrect your character. You have three books, each book have three worlds. And the manor have also three worlds. So you have to spend 30-45 seconds per world (thanks to the compass). It's possible to beat a level in 10 seconds.

Edit : while running, i did it under 9 minutes with no weapon (except dynamite), my only tool was the compass. Besides, i had three life points and i was hit one time ! So, the luck (big luck) and enought skill are enought.