Atmosphere? Who plays a game for atmosphere?
Joking aside, I feel like YN's ambience will eventually grow stale with too much exposure and it goes from being beautiful to just annoying. Without any sort of plot you're basically torturing yourself for no good reason except to have a girl kill herself for no good reason. The Hell Maze, for example, might be tense the first time around, but subsequent treks through the area will leave you frustrated at having no idea where you're going, having to look at eye-searing red, listening to the same droning beat on a loop, and cursing fucking Toris for getting in your way. Unless you want to move at a snail's pace through the maze to avoid them. The whole game is like that. And there's no point to any of it.
Taking away any sort of plot leaves you playing as a boring RPG hero rather than "a troubled girl with a dark and mysterious past you must discern for yourself" which is infinitely more exciting because it's an actual character. Breaking the illusion of any sort of story leaves the entire game a dull traipse through a vast, empty dream world with a limited number of things to do, and after seeing it once, are you really going to go back for an encore? Are you going to go back and forth into Poniko's house turning on the lightswitch fifty times just to see UBOA again? Rewatching the event on youtube seems like it'd be less exhausting. And it still leaves you with nothing in the end.
YN isn't really imaginative nor particularly innovative. It was done a long time before in the form of LSD, and no one talks about that, despite it arguably being a far better "dream game" because it's actually randomized unlike YN, which is the exact same thing over and over. LSD is probably bigger too, and more elaborate. Despite this, no one's making any VNs for it, or merchandise, and it's certainly not getting any Steam releases.
It's caring about the game solely for it's appearance that's a large part of why it's starting to get marketed so much now. Who cares about it having depth, when you can be satisfied with adorable little Mado. Better yet, why not buy a big box of Mado phone charms, stickers, and keychains, and a FACE fridge magnet so your room too will capture the same sort of feeling that YN has and always will have. Also included is a free sweater, a morally questionable Poniko poster and a CD of game OST that have been looped for sixteen hours and a collection of reassuring phrases along with it, with lines such as "Yume Nikki is totally real" and "Monoko is best girl".
I'm not saying YN is a horrible game by any means, I just think it's kinda overrated for what it really is and that people tend to overhype it a bit too much. Which leads into Kikiyama selling his soul for all the money that the countdown stunt is gonna reel in with the upcoming phone game, phone game ad revenue, phone game in app purchasing, VN, VN DLC, plushies, manga, anime, unknown other project, official Mado vocaloid, and all sorts of other merch that rapidly devalues and debases what Yume Nikki once was. Along with the inevitable shilling from youtube LP greats like Markiplier, MatPat, and Pewdiepie.
Look at what happened to fnaf. It coulda been good, for what it was. Having a fanbase of ten year olds keeps people from taking it seriously though, but at least Scott Cawthon is loaded and no longer suicidal. He didn't care for it in the first place however and just made it cause he was pissed. The story within it is super weak and the gameplay is kinda just Night Trap or Double Switch with Weeping Angels. But the typical "ghost children and murderer" plot does sorta help with the game's atmosphere. Not very well, but to a fault. It's more nonsensical anyway and, again, he doesn't give a crap about it.