Per 
Note from the creator of this page:
I am not going to do all of them because there is like 5 only so yeah.
The Negative levels of SCP-6400
Level -1 "Glitched Halls"
Level -1 is the first Negative Level below Level 0.
Level -1 is an infinite hallway that has doors on either side. The Hall is made of white painted walls, and black painted doors. Each door leads to either Level -2, Level 0, or Level 2. This Level is the safest of the Negative Levels so far, but that's not to say it isn't dangerous.
When inside this Level, you will no longer hear the hum-buzz of Level 0. Instead, you may hear slight piano noises in the distance, but the source of the noise is unknown. The deeper you walk through this hall, the slightly louder it gets, but you still never seem to get closer. Your vision seems to get more static like effects while walking too far down the hall. During this time, you can hear some old advertisements from around the 1930's era through the static noise. Soon, your vision becomes black and white with a static effect. While this event plays out, you can see people in old Business suits, although their human features are completely invisible to the human eye, the only thing visible is their attire. You may also hear the chatter of many beings mixed with the sounds previously mentioned. Almond Water puddles can also be found on the floor during this event, dripping from the ceiling.
The Wanderers that made it this far have always turned back at this point, and when they do, they end up talking about an unknown Entity that they simply call 'Nutrisha'. Further expeditions will be started to explore Level -1. This Level will for now have the designated difficulty level of 'Difficulty Level 2' until further notice and exploration.
The Basis of Level -1 is basically that it is one of the smallest Levels in all of The Backrooms (relatively), as it seems to consist of only an endless hallway. You cannot access Level 1 from here. It is recommended that you try to exit to Level 0, though, if you are feeling particularly adventurous and have a ready supply of Almond water, it is safe to exit to Level 2. It is strongly advised to never go to Level -2. From this level, it is very easy to slip into Level -2, which is extremely dangerous.
Level -2 "Overflow"
Level -2 is the 3rd Negative Level of The Backrooms.
Level -2 consists of only hostile entities, and some of the most sinister at that. Explorer Aryaman barely escaped with his life from a gigantic evil creature in this Level. Almond water seems to be available at this level, although the safeness of this water is confirmed, it is noticeably cloudier in appearance. Falling shafts from other levels can also lead to Level -2. It is very difficult to escape, yet this level seems to draw in explorers. Never go down to Level -2 at will.
This level is thought to be split into multiple significant sections, or areas. Most of these sections (apart from the area listed below and the area is known as "The Hall of Dull Flames") are unconfirmed and should be regarded as rumors until confirmed to exist by reliable sources. The area listed above is known as “The Pool”.
The section known as "The Hall of Dull Flames" is still relatively unknown, as there have only been two encounters with the area. It differs from the best-known section greatly. u/LoggoMyDoggo stated that the level resembles the layout of Level 0, but the walls are a stained baby blue with a white carpet equally stained. The fluorescent lights line the ceiling, but give off no light, providing nothing to the level but the maddening hum buzz present in previous levels. The walls are lined with lanterns that house flames that provide an ominous blue hue to the room. The color of the flames change color at random intervals, and it has been rumored to be linked to dire consequences to anything that moves in the light of the red flame. The distorted sound of a piano can be heard in the distance of the level, playing anything from Mozart to Tip-toe thru the tulips. Skin Stealers inhabit this section, and they also obey the red flames of the room; halting any movement when the red flames of the lanterns glow. No other entities have been reported on this section, but u/LoggoMyDoggo reported seeing the red vest of the baby feelings hanging on one of the walls.
There is another reported section, known as "The Abyss", but akin to The Hall of Dull Flames, it is still very much unexplored, as only 1 person has reported exploring it so far: u/Minion142. The Abyss seems to be a never-ending room of darkness stretching on for what seems like miles. Only one entity has been found here.
There is a fourth reported section of Level -2 known as The Kafkaesque Maze also explored only by u/Minion142 Which is a purple hedge stretching on for miles…it is also the hub for a being known as The Civic.
There is one report of a sort of "hub" connecting the various sections of Level -2, resembling a hotel lobby, but this is unconfirmed. Furthermore, it is likely not accessible from within the other sections of the Level.
Level -3 "Reflections"
Level -3 is a level composed entirely of mirrors and is very disorientating.
Level -3 is still mostly unexplored, but someone has managed to retrieve a picture. It seems to be built fully out of mirrors. Entities, which are mainly hostile on this level, are common, about as common as on Level 3. There are several types of entities in this level, including strange floating glass icosahedra nicknamed "disco balls", the omnipresent hounds, and one unseen entity that changes your appearance in the mirror.
In some cases objects can pass through certain mirrors in -3 and become physically reflected; doing this is not recommended, as it seems to be irreversible and is rumored to be dangerous. Under absolutely no circumstances should one attempt to pass through a mirror on -3 oneself.
Apart from sounds made by hounds and human explorers, this level is entirely silent. WIFI is available — it can be accessed similarly to the network on Level 3, except the password is instead "itsawyou". Wireless charging ports are occasionally available, taking the form of unmarked, seemingly random locations on the floor.
Level -4 "The Forest Of Calamity"
Level -4 is a massive forest full of genetically invulnerable animals.
Level -4 is a huge open forest, expanding for hundreds of thousands of miles in each direction. It's inhabited by animals that look similar to animals on Earth, like bucks, bears, snakes, and birds. Unlike regular animals, these animals seem to be more aggressive, and the skin of the animals is made of reinforced scales that seem to be invulnerable to damage.
Level -5 "Snowscape"
Level -5 is described as a field landscape with a layer of snow.
Level -5 is described as a field landscape with a layer of snow. Unlike most other Levels, Level -5 appears to be completely devoid of any entities. Traveling in any direction will eventually return from the rear of where you started. Because of this, it is believed the overall space of Level -5 is smaller than most other levels. Deep within Level -5, a small concrete building can be found Resembling a WW2-Era Pillbox with a door on one side and a small stepped gun embrasure on the other.
Peering into the embrasure is described as pitch-black, Although entering the door on the other side appears a hallway similar to Level -2's "The Hall of Dull Flames" The only difference being that the light stays a blood-red color, The hallways are described as "Neverending" With a pattern of small placards on the wall reading "NEW YEARS 1945". The hallway is seemingly infinite, however it is unclear if it is or if its length projects the feeling of infinity.
Littering the hall as well, lie WWII propaganda posters. All of them originating from varying countries. They all appear to be in their languages, Japanese, English, German, and so on. Smiles shine on the posters, unsettlingly. The seeming war propaganda has faces that appear slightly off-putting. Piercing eyes and faces too happy to convey the seriousness of war. Some of them too worn to even be read, their faces yet a bit too distinctive amongst the aged posters. Miles deep, a few old war gas masks have been found. Their color and condition display the age clearly, but they are seemingly intact, aside from the filter. If a filter replacement could be fashioned, they might come in handy.
Level -6 "Mystery Mines"
Level -6 is commonly described as a cave or a mine. There are little to no hostile entities.
Level -6 is commonly described as a cave or a mine. There are little to no hostile entities. Few have been in Level -6, and it is unknown if it exists, as there is very little material proof, and most of the traces of its existence are rumors. The first user to have reportedly found it was FunBricks1.
There are what appear to be people without eyes who mine throughout the cave, and are open to trade for supplies. They also appear to somehow see very well, despite lacking eyes. Not much information is known at this time, but this will be updated, as The M.E.G. is exploring Level -5 to find an entrance.
Level -6's lighting is greatly varied, but it is believed that the deeper into -6 you go, the darker it gets. The eyeless people who have been found through the level insist that they "lost their eyes" because they "went too deep" inside the level.
Level -7 "The Cruel Town"
Level -7 is deadly and toxic, which is recommended to be avoided.
When you first enter level -7, it resembles an abandoned mining town. You can eventually leave the town, and if you do so you will find endless fields, but it is recommended to avoid doing this, as the fields are full of hostile entities that do not enter the town due to its anomalies.
The town itself is full of mine entrances, some of which are believed to enter Level -6, though this has never been confirmed. It is not based on a real town nor does it seem to be from any kind of country in nature. The signs are complete gibberish but show drawings of people in distress and sickness.
The town is either sentient or alive in some capacity. Doors and gates will shut randomly, and lock behind you. One survivor reported the gates to a cemetery inside of the town closing shut and locking themselves. The survivor nearly died of this because at the time the mist was coming near. After a recent successful communication, it is known that the town is aware of the suffering it causes and is even capable of controlling the mist to target specific people.
In the center of this town, there is a highly radioactive factory. It has never been possible to enter the factory, as it’s toxicity and radiation will kill you first. The factory used to be some form of a chemical waste plant, which could be the source of level -7’s high radiation.
Approximately every 5 hours, the factory will begin to release a mist. The mist is usually described as dark grey but is sometimes a deep green or blue. The mist is incredibly dangerous to inhale and will begin to cut the lungs and damage the throat of any victim who inhales it. Interestingly, the mist is largely carbon-based in form.
Anyone who inhales the mist will die. Within the next 3 hours, the mist will cover the whole town. During this time your only option is to run into the fields, which are infested with entities.
Note: This is it.
