1.1 General Advice
Please don't use this guide if you haven't tried to find or solve these riddles/secrets yourself!
Feel free to use it when you don't find the secret on your own after trying for some time, or if you don't have the strength, patience, concentration or time to find or do it on your own.
I don't want to judge you for what you do with your life or how you play, I just want you to know that finding/solving these secrets on your own may be more satisfying.

1.2 Guide Version: Last edited: See info on the right! ------------------------------------------->
This guide may contain false or incomplete information, because of recent updates.
| Game Version 1.0.0.3

1.3 Sharing:
You can share this guide, e. g. to help people in the discussion forum quickly without having to write a long answer.
Use Right click + Copy on the link below and paste it into the discussion post (or use the "Share"-button above).
https://steamoss.com/sharedfiles/filedetails/?id=2654434583

You can find two arcades that let you play the (gem) combination game "Gembine".

Coordinates:Canaveral: 1612° 507° and Sunburn Desert: 518° 583°

Methode:
Tip 1:
It is basically the game "2048" in a different graphical format (gems instead of numbers).
Tip 2:
Rule of thumb: You want to play (mostly) with 3 direction keys and concentrate higher level items in one of the four corners of the square.
Tip 3:
Avoid low level gems on the lines adherent to that edge. Try to place low level gems in the middle. That way they have two possible directions from which another low level combination gem can come from.
Tip 4:
When getting above 15.000, use the preview on the right to make better decisions.

What follows:
Once you beat the highscore of ~54.000 points, the game will give you a message:
(You can't find the buried arcade without beating the highscore!!!)

"Something strange is happening. The high score has changed to:
@ 215° 713° " [Solaris]
What you get:
2 mana shards, 4 electronics. - every time you go there after dying! (Maybe that's a bug?)

You may have wondered how to get to the chest near the waterfall in Westport at ~ 339° 338°.

Tip 1: Carefully inspect the environment.
Tip 2: Take a leap of faith.
Tip 3: Ever heard of the philosopher's stone(s)?

Solution:
There is an invisible walkway, between the stones in the water, starting from the coordinates above.

What you get:A recipe.

Have you ever tried to jump into the mana crater in Polaris and ended up getting teleported onto the top of the nearby hill?

Well, jumping off & dying or taking the (mana) amber pills are NOT your only options to get off that hill!

There is a way to get off it ALIVE!

Tip No. 1:Jump off anyway.
Tip No. 2:It's going to be a rocky road down there.

Solution:
You can jump down onto the - conveniently placed - two big rocks on the levels below (if you haven't destroyed them already). This - unfortunately - doesn't always work, because the game sometimes doesn't register you falling on the rock. It works most of the time and is actually an intended (secret) way to get down AND teach you a new mechanic if you haven't picked up on it already.

Somewhere on the map, there is a door facing the ocean side with small forecourt that is enclosed by a railing and seems inaccessible. A red chest can be seen on the concrete forecourt.

Location:
Tip: Name of Kanye West's kid = Area where you have to look
It can be found on the Frost Horn at 179° 284°

(Screenshot does not contain the red chest next to the door, because I already destroyed it..

What to do:
Your target is the red chest next to the door and the content of it.
I suggest destroying the chest with carefully placed grenade throws. This avoids the "death by falling" problem altogether.

Alternatively:
Do a (precise) jump onto the red chest to get down and loot it. If you hit the ground next to it, you die. After jumping down there is no way back up or over the railing, so you have to use the suicide pills to get back to the last camp fire. - Achieving this is difficult!
Video of someone doing this:
https://youtu.be/9Is3LlLaRP8?t=37
{A big THANK YOU to user Garikos for posting this video tip! I died when I tried jumping down which is why I used the grenade strategy.}

What you get:
You either get the recipe "Mushroom Salad" (= power attack damage +50%) or a bunch of materials when you have already cooked the recipe (with the cooking guide for example). You also should get the recipe when you destroy the chest with grenades.

However the angular vault door can also be found next to the shelter bunker on the Crown(*1), near the landing pad(*2) and other locations. It is highly likely that there is a part of the Undercrown that is not accessible to us yet that will allow us access this red chest later on.

(*1) Door 1 (@Crown 934° 472°)

(*2) Door 2 (@Crown 956° 469°)

(*2) Door 3 (@Crown - Landingpad bunker)

(*2) Door 4 (@Crown 1019° 508°)

You may be missing an enemy type in your "collection" when opening this section in the menu, but want to find out what it is to complete your encyclopedia.

Tip 1:Don't forget your water in the (Sunburn) desert.
Tip 2:It will only hunt you when you are already dead.

Solution:
Vultures. You can find them in the "Sunburn Desert".

What to do:
You need to collect the hunting rifle and go up the hills in the desert to be on a similar height level to the birds (you cannot shoot upwards much). Then wait for them to come remotely close, aim and hit the trigger. You might have to aim UNDER them to hit them. That's because the "hitbox" (the invisible programmed grid/raster where you have to aim to land the shot) is actually under the bird not on top of the graphical model. The optical marker (cross) will show on the bird if your mouse is within the hitbox while aiming.

Alternatively:
Use the Khopesh (ranged attack). The cone of green flames actually goes quite high, although you would not expect this by how "flat" the effect looks. You still have to use an elevated position though.

What you get:
One egg per kill and an encyclopedia entry. That's it. If you want the full entry (enemy name/type | description | drops), you have to hunt at least 8 in total.

The (single) red telephone can be found in the king's bunker on Ark level 2.

What about it?
When you interact with the red telephone, you get the message:
"The phone is not ringing yet" - indicating that there will be an event later.
The map next to it shows you some red spots all over the island(s).
Those red points are...
... - contrary to what you might assume - NOT the (mana) camp fires the protagonist has built. They are actually markers for dense populations centers (cities etc.) which have been overrun by the zombies.

What to do:
As of yet unknown.
We assumed before that you likely have to reach ascension level 3 on ALL link towers on the map and totally clear the map of enemies. That is - at least for the current version of the game - unfortunately incorrect (disproven). There were a few theories around, including the theory that there are telephones at the marked spots which have to be "activated" in a certain order, but they got ultimately discarded when one of the devs announced on the Discord server that "there is currently nothing you can do regarding the phone".
...so... yeah... sorry guys. Let's hope for an implementation in the future!

Trivia: It may be plausible to claim that the theory about connecting red telephones will make sense in the future. The reason for this is the little shed @ (Crown) 908° 393° which can be found close to the shelter of the "king", containing a lot of red telephones inside:
(A big "Thank You" to the user "Thom" in the Discord for providing us this picture)
... as well as the sidequest "Phony Shipment" in which the information can be found that before the newest outbreak of the pestilence, a big shipment of telephones has reached the island and has been shipped to Ft. Darrow (maybe the starting point of the quest).

The large phone shipment should be loaded on Tuesday morning for delivery to Ft. Darrow.

What you get:
Nothing. The quest & reward hasn't been finished and added into the game (completley) yet.

Trivia:
The "red telephone" is probably a reference to the "Moscow-Washington-Hotline".
This system allows direct comm. betw. the leaders of the USA and the Russian Federation (formerly: Soviet Union). Although being known as the "red telephone" in pop(ular) culture, the hotline was never a telephone line, and no red phones were used. Although being proposed before, it was finally established after the Cuban Missile Crisis in 1962, since messages sent through the indirect comm. channels took 6-12 hours to decode - a dangerously long time for a confl. that could have sparked a nuclear war.
The 2 countries signed the "Memorandum of Understanding Regarding the Establishment of a Direct Communications Line" on June 20, 1963, in Geneva, Switzerland (through repres.) - the 1st time they formally took action to cut the risk of starting a nucl. war unintentionally and therefore establishing the system.
(Click here to read more on Wikipedia)[en.wikipedia.org]

Have you found it yet? You can easily find it on the map, although it does NOT show up as a point of interest (POI).

Tip: Ever played "Blind Man's Bluff/Buff"? The door is also at a "warm spot". Some may even say you could get a sunburn!

Location:
You can find the "Surreal door" in the Sunburn Desert at 612° 672°.

How to open it:
It can only be opened at a certain time of the night* (it will glow in a ghostly blue) with the "Surreal Key". *(I have found the door to be active around 23:00-04:00 / 11 p.m. - 4 a.m.)


Getting the surreal key is the hard part:

You have to clear ALL tombs without dying, open the black pyramide and pick up the surreal key which lays next to your old skeleton. Dying within the tombs does NOT count.



Explanation:
If you die in the game, you leave a skeleton. When you return to that skeleton, you can loot it. If you die before reaching it, your old skeleton vanishes and gets replaced by the more recent one.

As we come to know, the protagonist is/becomes the one-armed king (oaK) when he crashes with the escape pod in the normal ending. The oaK gets killed when the archaeologists, under their leading researcher, Abby, drop cyanide gas into the tomb of the oaK (he was buried alive, because he is immortal and always gets revived after death at the closest source of mana = camp fires).
OAK - for unknown reasons - has the surreal key. So to get it, you have to clear ALL of the 20 tombs in the game to get the 20 round blue orbs and reach the pyramide tomb of the oaK with a gas mask without dying/with the OVERALL death counter being zero! (So if you have already died, you have to use a different save slot or use the alternative solution described below.)
You will find the skeleton of the oaK in the tomb, which you can then loot (since it is technically your last point of death).
As soon as you die once, your skeleton in the tomb vanishes and the most recent skeleton appears on the map.
If you manage to clear all the other tombs without dying and to find the skeleton of the king, you can loot him and he will drop the SURREAL KEY.

Tip: You can create a new game in the main menu under the second tab "Save Slots" and just create a second save slot. You can also try to Alt + F4 your way out the game if you have died to avoid detection of the death by the game and doing everything all over again.

Alternatively: Use the mod-/devkit to unlock the key for your character. You will have to
(0) Get the dev kit from the 10tons Discord by asking other people nicely - @10Tons (server is public & can be found using the regular search function)
(1) back up your save first (Save route: C:\Users\[UserName]\AppData\Roaming\10tons\DYSMANTLE\save),
(2) then start the game and click on continue
(3) press the "DEV"-button in the bottom right corner and
(4) write "SURREAL_KEY" into the empty space of the cheat window under the "KEYS" category.

Doing all this is NOT needed for any achievements.

What you get:
Currently: Nothing.

The devs have hinted that you will be able to get to other parts of the maps through it once everything is finished (probably a separate "ghost room" with doors leading to previously inaccessible parts of the map). They have added the door to enable players to theorize about it and aquire the required key before releasing the level/connection. They have clarified already that it won't lead you to the currently inaccessible parts of the map in the East of the Crown.

You can find a little house with a table in Westport @ 365° 325°.
It kinda resembles someone having a little tea party... (and the floor is also quite unusual). Maybe I just have gone too deep down into the rabbit hole?


You can also find a sign nearby, inviting you to join the tea party.


You gotta love the cultural references in this game.

Trivia: The first Matrix movie is also making many references to "Alice in Wonderland" (besides others, like Plato's "Allegory of the cave". E. g.: Morpheus tells Neo to follow "the white rabbit" - as Alice did in the book.
Backup link: https://youtu.be/6IDT3MpSCKI?t=69
When offering Neo the red pill, he promises Neo to take him to "Wonderland" and "to show him how deep the rabbit hole goes" if he takes it.
Backup link: https://youtu.be/zE7PKRjrid4?t=93

Maybe the devs are telling us that the world the protagonist is in, isn't real according to the game lore itself?

Maybe it's just me, but the way the three enemies are placed in the Sunburn Desert @ 756° 810° reminds me very much of some iconic cinema scenes, especially from the movie "The Good, the Bad and the Ugly" - especially since the scene is in the desert. The devs might just love Western movies.

[THEORY CONFIRMED BY DEVS!]
This "Easter Egg" is in quotes, because it is not really hidden, but its meaning and references might go further than one might expect.

There is a diner in the desert, called "The ExtraDinerrestial Restaurant", using claims that the island has been visited by extraterrestrials (who brought the ancient civilization on the island their advanced technology) as an advertisement. The decoration in the diner also follows that theme.

While one might speculate if the crash pod-crater and the "thing" that supposedly "crashed in the desert" are the same, the diner is probably a reference to the diners close to Area 51, Nevada (US) and/or Roswell, New Mexico (US).

The Roswell incident - which the diner refers to in some extent - happened on July 8, 1947 and is quite controversial. While some people claimed and claim that a "flying disc" crashed there, the Air Force, who retrieved the wreck and sealed off the crash site (it was later claimed to have been a balloon from the top secret project "Mogul"), has denied any such claims.


The reference to Area 51 is of course the (military) Mercury Installation in the South-West of the Solaris desert. It even has airstrips. - If you didn't know: Area 51 was, until its existence got confirmed by the CIA in 2013, a top secret military installation whose (official) purpose it was/is to conduct tests on xperimental aerial vehicles like the SR-71 or the F-117 Nighthawk - at least back in the time of the Cold War (1947-1991) with the Soviet Union. The nearby dried up salt lake could be used for emergency landings/roll-outs by the planes and the isolated region allowed to keep tight control of who would see the design of these new aircraft. The internal name for the site was "Groom Lake", because of that salt lake. The salt lake can also be found in the game and is on the East side of the base as you can see on the game map/satellite overview.


...Maybe that's a hint towards where the mana on the island is actually from?
After all, the source can't be the crash pod loaded with mana, because you can find more mana on the island than you put into the crash pod before you fly off and the loop starts again. Also: Why else would the diner be close to the desert instead of the North close to the crash site of the pod? The hangar in the South still can't be opened (Maybe it leads to an underground site?). The devs have also hinted at the Undercrown being "as big as the world map", so it might be possible that the Undercrown has connections all over the actual world map. A similar hangar can be found in the North.

The "Big Brother" easter egg is actually not one easter egg, but two.

One easter egg can be found as text in "the Artist's House" @ 273° 404° in Westport.
There is a single (lonely) straw puppet in the house, (virtually) complaining (in the text note) that all of it's friends have gone somewhere else in connection to a "Big Brother".
This may be a reference to the novel "1984" in which an unknown (totalitarian) entity with the same name controls the population. The ambigous text note is just a little story snippet that apparently adds to the story of the following easter egg:

Somehow connected, but actually another easter egg (according to the devs) can be found @ 266° 399° Westport.
There you can find the other straw puppets surrounding a bigger figure or statue.

The straw puppets resemble little robots with round shapes. This is an hommage to "Nier: Automata"
where the robots look very similar.

The UNRESOLVED MYSTERIES™-section is here for the mysteries of the mysteries!

Have you found a myth-enshrouded "thing" in Dysmantle? Or have you found a solution for a riddle or an already discovered mystery?
Feel free to write a comment and be remembered here for E T E R N I T Y (as I will add your username to the discovery)!*

*(Eternity may cause pestilence. The writer of this guide does not guarantee your medical safety or wellbeing when commenting under this guide.)


SOLVED!
@ 1036° 741°

Discovered by the legendary parliame aqua
ANSWER: Devs have been asked: It currently has no function, it just looks mysterious. :D

Unsolved:
The original source of the mana.
The mana on the island - contrary what one might be tempted to think after experiencing the ending - can not stem from the mana that has been loaded into the escape pod before the crash, because you can find more mana on the island than you load into the escape pod. This leaves only one possible explanation: The mana is from another source.

The location of Abby's grave or her whereabouts
While we learn that Abby saved the one armed king who was locked inside the pyramide tomb by flooding it with cyanide gas, we never learn what happened to her afterwards. The one armed king makes a reference in one of his recordings, mentioning her name and therefore revealing that they have met afterwards, but says nothing else. It is very well possible that Abby and the protagonist had kids of their own or a different kind of relationship.

Maybe the icy grave close to 201° 123° is her grave?
https://steamoss.com/sharedfiles/filedetails/?id=2714381598
You can reach the grave by jumping/rolling on the little island from the plateau above. Equipping items that increase your walking and dodge roll speed will be helpful (street warrior jacket etc.). There is no reward for doing so.

The partners of the protagonist
The ancient stone tables reveal that the one armed king has had several descendants who were buried alive in the tombs. It is never revealed who was/were the mother(s) of those children though.

Who is the psychopath on the "Sanctuary Farm" and why did he/she go crazy?

The "Mana tunnel"
East of the North Star installation @ 480° 137° in Polaris, there is an entrance to an underground base, closed up or bureid by an avalance with mana activity. When you get close to it, you get slowed down by the mana presence, even if you have the wristwatch equipped.
Some journal/wall notice in the North Star Installation also makes a remark about "mana tunnel to which men were send to, but didn't return" and the sign next to the entrance forbids any entry.
The devs have confirmed that this is NOT a coincidence or a bug, but intended. We will be able to enter the tunnel later on, but at the moment, the players are not intended to enter it yet.
As far as I can tell it is also impossible to enter it (for now), although it might be possible to glitch through the blockade. I don't know if entering is possible if you manage to slip through though.

Why are there ghosts of deer, but not of humans, reindeer or other animals?