The following text contains spoilers, but who can they harm?
As you may know, there is a game called "The Mold" created by Eric Gurt in 2010.
The name of this game can be interpreted in three ways: the shape as the key to the puzzle in the first level, and the mold as the main player who is imprisoned in the cell of correction 9 as a test subject to become part of the mechanism for saving mankind to the past. And mold because of Noir Lime, since he can be found on the first level as a dark green test subject.
C9 needs to test people's: shooting skills (Level with a revolver), resistance to fear (Meeting other test subjects, who failed, crippled), wit (puzzles), genetic ability to use a teleporter and much more.
The plot is based entirely on the memories of the Marine before the activation of the time machine. And that's why it's not 100% accurate. C9 didn't have enough time, so the facility was built with bricks but with advanced technology.
Why do I call the main character a marine? It's simple:
1. He is human because he can read English; Knows how to use weapons and other things.
2. Says nothing, like a marine from pb1 before meeting with an ally.
3. He knows what noir lime looks like because he met him at the gate on the first level with the sign "Survive" on the ceiling. Also, the Marine breaks the teleportation system with a pistol in order to pass the exam, which causes him to teleport incorrectly in time.
4. "I do not say farewell" - this Marine's quote at the end of pb1 also means that he never said goodbye in his memory and did not say goodbye to Noir Lime at the first meeting (at the wooden gates) (and did not say goodbye after, the second time).
5. At the end of the game, the player only has a pistol, just like the marine. (The gun has been upgraded due to an between time shop, also 1 slot gun added like saw from the mold).
6. The player survives Level 2 in Plazma Burst 2 because he knows the red ray kills.
7. Noir Lime doesn't know how Killing Ray works, so he stands still in pb1 when he first meets it (Marine already knows this because of The Mold's starting level)
If that's not enough for you.
8. The Mold ending uses time machine technology.
Also, the doors and concrete of the mold are the same as in PB2. And you could see the sky at the end just like at the beginning of Plazma Burst 1.
This is just a theory.