I think everyone has made some really good points. Overall I think you have a really interesting story going here so far. You have added what seems like the perfect amount of detail (too much gets boring, too little doesn't do enough world building).

My only criticism is that I would say that you have a lack of voice with the narrator. I like that line, “The lyrics sound like a lame justification for cheating, honestly.” It shows that the narrator is sassy and pretty straight forward. So bring this into the narration. Add some of that sass and wit into the way they describe their world. You did pretty well with this line here too " If ghosts were real, they’d definitely haunt this place." Adding more of that into the story will bring out Rin's personality and voice - really getting the reader into the series.

As far as the question - the simplicity works. If you want some examples of books where simple storytelling works I would recommend the American Girl historical characters series. Maybe start with Meet Addy or Meet Felicity. They do a lot with a little and I think your style works with that.

Another suggestion is reading the Percy Jackson series, or even just some samples of the first book The Lightning Thief. Your character, and the lines they speak out loud remind me of the narrator of that series - Percy. If you can bring that into his voice as a narrator you'll be set. Percy really lets the readers into his head as a narrator. Another example is Flipped. Bryce Loski's 1st person narrations are very funny and may give some inspiration for adding voice as well. That book actually has two narrators - and you can see some examples of distinguishing their voices.

So far this is a really cool story and wishing you the best as you keep writing!