Reminds me of a giant hotel/apartment I explored in a dream of mine. Endless hallwalls and even going back the way you came would often lead you to different sets of rooms. My apartment seemed to gain extra rooms at random and at one point connected to a giant... I guess gymnasium or warehouse.

Trains with only floors sounds fun if dangerous yeah.

wanna live in the dream world

Yes! I traveled like this so many times...
Most part of times you have to jump off suddenly and without even knowing where you are.

ah, i'm glad to find out we take the same train at night

it's super disorienting but it makes so much sense at the time

There's no OSHA in that universe.

everything keeps shifting, how could they even work?

the manual would be unreadable by virtue of writing failing in dreams most of the time too

The Dream OSHA Inspectors. Make up rules as they go, serve cruel and unusual punishment swiftly and without right for appeal or even defense, appear unannounced and unexpected, demand impossible, punish unrelevant, praise unintendedly safe, consider factors beyond common comprehension and impacts on species unknown. Manual? Its text, by virtue of dreams, never reads the same twice. That's no excuse. But your escape is in redefining purposes. Darwinian Train, built to reinforce the genetic pool of the population through culling the weak and unbalanced. Corpses must be removed in timely manner, blood neutralized through holy water dispensers to prevent abuse in summoning rituals, and periodic decapitation bars across the way must be painted in yellow and black stripes of properly calculated visibility to only cull sufficiently inattentive.