well, i dont thin k you can compare Narnia to LOTR either. I wouldnt say OS1 is a playground, that sounds soulless. Theres artistic ideas there, they just dont take themselves seriously.
Its more about a personal journey rather than a grand narrative.
I think i found a more apt comparison.
OS1 is more like a Studio ghibli film than a fantasy novel. its got those ideas that COULD make a narrative, btu kind of liters them on the side while the main journey is just some protagonist doing some dreamlike stuff