I'm not entirely sure as I haven't played it specifically. But generally, a visual novel often has a story with different plotlines, characters, and interactions. It might be set in a fictional place called Crystal City and could involve things like adventure, relationships, or mystery.
I don't know for sure, but usually in a visual novel, there is a protagonist. Maybe in 'Crystal City Visual Novel', the main character is a young adventurer exploring the city.
A 'Crystal House Visual Novel' could be centered around the concept of a crystal - themed house. Maybe it's a story where the house has some special powers or significance. For example, the crystals in the house could be the source of magic that affects the characters' lives. It could be a love story where the couple meets in this unique crystal house and their relationship develops against the backdrop of this magical place. Or it could be an adventure story where the characters explore the secrets of the crystal house.
I'm not sure specifically as I haven't played it in detail. But generally, a visual novel often has a story - it might be about the adventures of characters, their relationships, and could involve some sort of mystery or personal growth within the context of the crystal chameleon theme.
The main characters in 'Crystal House Visual Novel' are a mystery without more information. However, it's common in visual novels to have a protagonist, perhaps a character with a unique ability or a special connection to the Crystal House. There could also be supporting characters such as a local wizard who gives advice about the house's magic, or a family member who has a past connection to the place.
I can't really say for sure if'milfy city visual novel' is popular. There are so many visual novels out there. It could be that it has a dedicated following among those who like its particular style, story, or characters. However, without specific data on sales or the number of players, it's difficult to gauge its overall popularity.
You might need to look for specific triggers or items in the game environment. Sometimes, it could be related to solving a puzzle or completing a certain task.