I'm not entirely sure specifically as it could vary. But generally, a visual novel often involves a story with characters and plot developments presented in a visual and interactive way. 'Kodomo no Jikan' might center around stories related to childhood perhaps, with characters experiencing various events during that time of life.
Probably not. It depends on the content of the visual novel. If it contains complex themes or some mild forms of drama that might be difficult for very young children to understand, it may not be suitable for all ages.
End roll game fanfiction is basically fan - created stories based on the 'end roll game'. It could involve new storylines, different character interpretations, or exploring uncharted aspects of the game's world.
This 'isekai de saikyou maou no kodomo novel' could potentially be a story full of fantasy elements. The 'isekai' setting gives the opportunity for a unique world - building. With the main character being the child of the strongest demon king, there could be a lot of political intrigue. Maybe other characters are trying to use or manipulate the child because of their lineage. Or perhaps the child is trying to break free from the expectations set by their father or mother, the demon king, and wants to create their own identity in this strange new world they've found themselves in.
First, you need to be really familiar with the end roll game. Know its characters, plot, and the overall vibe. Then just start with an idea, like what if a certain character had a different backstory. And start writing from there.
This novel was called "Supreme Mad Soldier Pretty President". It described an existence that could compete with the number one on the Heaven List. It was called a human legend. In this novel, there were organizations and rankings such as the Earth, Heaven, and God rankings. I hope you like this fairy's recommendation. Muah ~😗