Unknown
 | |
| Floor # | 6 |
|---|---|
| Music | 'No Tomorrow' |
| # of Mini-Bosses | 3 |
| Mini-Bosses | Idol, Redcap, Twofold, Engorged |
| Bosses | Machine, Machine (Damaged), Machine (Original), Monolith |
Unknown is a special floor in that it can only be accessed after the player has collected all four seals locking its entryway. Once the player has collected them, they need only defeat Overlord on the fifth floor and use the northern exit after the battle to travel to it, as they would do to access any other floor.
Unknown is characterized by its dark, ominous atmosphere and especially difficult rooms. The walls appear old and cracked, and the dark background rhythmically pulses, showing silhouettes of damaged walls lit by what appear to be glowing pipelines. Rooms may contain new, difficult enemies or even mini-bosses that the player fought on previous floors as regular enemies. The area is so hostile that even tiles found within the rooms can come alive and attack the player. Shops and Upgrade Terminals do not generate here under normal conditions, though a Vault and Weapons Cache are guaranteed.
In addition to its unique form of access, the floor is also unique in that it houses many bosses that appear depending on which ship the player is using and on which difficulty setting they are playing.
On Normal mode, while playing as any ship aside from Overlord or Chaos, the player will face the default Machine battle. As Overlord, they will fight the damaged Machine. As Chaos, they will fight the original Machine. When playing on Hard mode, they will face Monolith.
If the player possesses the Err: Integer Overflow cartridge or has Looping enabled, the player will proceed to the seventh floor, Nowhere, after defeating the boss. Otherwise, the game will end.
Enemies
These are all the new enemies that can appear in Unknown, not including enemies from previous floors.
| Name | HP | Debris | Bestiary Entry | Behavior and Notes |
|---|---|---|---|---|
 |
Something is lost forever." |
Chases the player via the shortest route available. Fires a burst of three revenge bullets upon death, two of which are destructible.
| ||
 |
The essence of the past, burned to make future." |
Slowly chases the player, capable of passing through any obstacles in its path. Slowly blinks in and out of visibility. Cannot be possessed by Possessors.
| ||
 |
Fires a stream of bullets at the player, with 4 shots concentrated in the middle and 10 more around them in a wider arc. Eternal Sentinels spawn with an orange Halo that fires 3 additional projectiles independently of their attack, switching to another enemy upon the Eternal Sentinel's death.
| |||
 |
Fires three blood bullets at the player, and teleports closer to them if it doesn't have line of sight to them.
| |||
 |
Chases the player via the shortest route available. Explodes into six large bullets on death, along with a storm of destructible fire bullets that eventually disappear.
| |||
 |
Fires double damage bullets in a wide spread pattern outwards, as well as two bigger double damage projectiles towards the player. Will also let Crazy Ghosts out on occasion.
Releases its Soul Tank upon death, spawning 2-4 Ghosts, Ice Ghosts, Crazy Ghosts, or Lost Souls.
| |||
 |
It goes on and on and on and on..." |
Fires a massive spread of bullets shaped like itself, then teleports.
| ||
 |
Fires spreads of bullets at the player. When it does not have line of sight to them, fires bullets in all direction that wrap around the screen and go through blocks, similar to the player's weapons when they have the Phasing Keyword. Even when in line of sight, there is a 1/6 chance that any given attack will become the phasing attack.
| |||
 |
Teleports in and out of visibility, utilizes one of two attacks as it reappears: one has it firing bullets in a star shape from its center outwards, another has it firing in a spiral around itself while sucking the player in. Can only be damaged while open. Deals no contact damage.
| |||
 |
Teleports in and out of visibility, projecting and then firing two inward-sweeping lasers in the direction of the player when it reappears. Bullets emerge from the lasers as they connect with the wall. Does no contact damage.
| |||
 |
Disguises as a normal block, and awakens when all other enemies are killed. Chases the player, leaving a trail of bullets in its wake.
| |||
 |
Disguises as a large block, and awakens when all other enemies are killed. Slowly chases the player, leaving a spread of three bullets in its wake.
| |||
 |
Disguises as a suspiciously massive block, and awakens when all other enemies are killed. Stays in place and fires a tight spread of bullets around the room.
| |||
 |
Made whole. Trapped." |
Fires a laser toward the player, with bullets emanating from the laser, and then around the Mage. Will slightly alter aim depending on where the player is moving.
| ||
 |
Fires a laser toward the player, with bullets emanating from the laser, and then around the Mage. Bullets will fire parallel from the laser, similar to a laser weapon with the Pulsewaves Keyword. Will slightly alter aim depending on where the player is moving.
| |||
 |
Repeatedly fires three bullets at the player as it slowly moves towards them. After a while will enrage and release a burst of bullets around itself. While alive, the background of the room will be pitch black.
| |||
 |
Fires bursts of bullets around itself similarly to the burst attacks of Presence, without larger blue bullets. While alive, the background of the room will be pitch black. Clears the room of its projectiles once it dies; this can be used to clear the projectiles of other Insubstantials in the same room even if they are still alive.
| |||
 |
Effectively a Mini-Boss. Spawns four Block Locks in three waves that must be destroyed each time for the Ascended One to enter a vulnerable state. After all Block Locks are destroyed, the player must hit the Ascended One once to kill it. Fires large bouncy orbs that home in on the player, but can be pushed back by shooting at them (or with Bombs). When hitting a wall, the bouncy orbs will fire their own projectiles at the player. Each Block Lock wave completed spawns an additional bouncy orb into the room. Drops a random Unique Weapon when defeated, or a Cartridge when playing as Chaos or Skully.
|
Mini-Bosses
 |
 |
 |
 |
| Idol | Redcap | Twofold | Engorged |
Bosses
 |
 |
 |
 |
| The Machine | Machine (Damaged) | Machine (Original) | Monolith |
Trivia
- Under normal conditions, the player will not find a shop on this floor. However, if they possess the Cool Sunglasses cartridge, one will be generated. This is also the only way to see the Ascended One's dialogue, who will appear in the shop if they are present somewhere on the floor.
  | ||||
|---|---|---|---|---|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|