My Son's Room Leads to a Miniature World of Heavens

I pushed open the door of my son's room and was shocked. I actually came to a strange place (the world of cultivation). The people in this place were really very small. I hurriedly stepped back and found that I was back at the door of the room. I opened the door again and found another strange place (the fairy world). The immortals and beasts here were also very small. After trying several times, I ended up in a strange place. They were all miniature worlds and miniature people. It was either the ancient times of Gaowu, or the modern city of parallel time and space, or the parallel time and space of the future.