Uncertainty

the game is based on the idea that you don't know what's behind the door until you open it which relates to concepts in quantum mechanics (superposition, state function collapse etc.).

you spawn in a map that is an overlap between other maps and you are uncertain of which map it is, until you find a door which collapses that overlap and you are left with one of the maps and so does your weapons (Not Confusing At All). 

In simpler terms, imagine you start in a world that contains elements from different maps all at once. As you explore, you eventually find a door. When you go through that door, the world "chooses" one of the maps, and the entire environment becomes based on that specific map. It's like the game dynamically assembles itself from different possibilities, and the door leads you to one particular version of the game world.

then you complete objectives based on the specific  map you have been collapsed into.

Disclaimer: THIS IS AN UNFINISHED GAME , A PROTOTYPE AT BEST