I've been thinking about a version of the Backrooms that isn't quite friendly to age regressors, but isn't actively dangerous: liminal spaces and age regression fit together very well for me because of the dissociation I connect to both of them.
Here's my initial thoughts: if there's a "level" or version of the backrooms you'd like to explore, feel free to drop me an ask!
The yellow hallways stretch on for what feels like forever. The hum of the fluorescents is ever-present, occasionally drowned out by a period of rushing air: the air conditioning, or heating. You're never able to tell which, since the space is always a perfect room temperature. You're not hot, and you're not cold.
The tightly-woven office carpeting ripples under your feet. If you take your shoes off, it almost tickles your toes. Eventually, your feet will get sore: the carpet isn't thick, and you can feel the chill of unforgiving concrete under its feeble layer of protection. You'll have to keep your shoes on if you're walking a long distance.
Sleeping is difficult in this tangle of well-lit halls, but you tuck yourself into a corner and put a sweater over your head and you can snooze for while, until the roar of the air through vents wakes you again.
Time moves strangely and you're never sure how long you've been here, but you're never hungry. The stretch of the hours and constant exhaustion pulls you down into a regression you can't fully climb out of: in your adult hours, you're no less confused by your surroundings, so it feels like there's less and less of a reason to fight it.
In your pocket, a box of crayons: you can't remember where you got them from. You can draw on the walls, sprawling crayon murals up and down the yellow wallpaper. Once you leave them behind, you'll never find them again, no matter how carefully you retrace your steps.
This place is not comfortable, and you do not feel at home here. Nevertheless, there is something daring and fun about playing in what feels like an empty office. This is a place for grown-ups, with its harsh lighting and boring carpet. Yet here you can roam, unattended and curious: and the hours or days or minutes, whatever they might be, pass without any way to mark them.