Well, Mugen Visual Novel is a concept that fuses two different things. Visual novels are known for their story - driven gameplay, with lots of text, choices, and different story paths. Mugen, on the other hand, has been associated with creating custom fighting game content. In a Mugen Visual Novel, perhaps you could have a story where the outcome is affected by fighting elements. For example, characters might battle to progress the story, or their fighting abilities could be part of their character development in the narrative.
The main theme is often about the unreliable narrator. The protagonist's alcohol - induced hazy memories and her attempts to piece together the truth about a missing woman. It also touches on themes like domestic abuse, betrayal, and the complex nature of female relationships.
A key feature of mugen games with story is the character development. Since there are often a large number of characters from different sources, the story allows for their growth and evolution. Another feature is the plot progression. There's usually a main goal or conflict that drives the story forward, like in "Mugen Souls" where Chou - Chou's quest to rule the multiverse is the central plot. Also, the story can add replayability as players may want to experience different story paths or outcomes.
The main theme is often about the brief but impactful encounters in life. It shows how a chance meeting on a train can leave a lasting impression on a person.