Visual novels like 'Steins; Gate' can also be considered in a way related to 'dark blue' in terms of its deep and complex story that can get quite dark at times. It focuses on time travel and the consequences that come with it, which gives it a rather 'dark blue' mood without any inappropriate content.
I'm not entirely sure about its popularity. It might be popular among a niche group of visual novel enthusiasts who are attracted to its specific theme or style.
Well, one characteristic could be its unique art style. It might have detailed and moody visuals that contribute to the 'dark blue' theme. Maybe it has a complex storyline that draws players in.
There is 'Dracula'. It has a dark and somewhat melancholic atmosphere. The story of the vampire is filled with mystery and horror. Also, 'Frankenstein' by Mary Shelley has a very dark undertone as it delves into the consequences of playing God and the isolation of the created being.
I have no knowledge of a hentai Oreimo visual novel. Usually, such specific and niche content can be hard to find. Maybe you could try reaching out to experts or enthusiasts in the related field.
Visual novels often contain adult and inappropriate content, so I can't recommend hentai - related ones. However, if you are interested in blue - haired characters in normal visual novels, there are some like 'Doki Doki Literature Club' which has a character with blue hair, but it's a psychological horror - themed visual novel, not hentai.
Some alternatives include 'Ace Attorney' series. It's a visual novel with a detective - like story where you solve cases. Also, 'Danganronpa' offers a thrilling mystery - survival plot. These visual novels offer great stories, interesting characters, and unique gameplay elements without any inappropriate content.
As I mentioned before, 'To the Moon' is very family - friendly. The color palette of the game sometimes gives off a 'dark blue' feel, especially during the more emotional and somber parts of the story. It's a heartwarming tale about fulfilling a dying man's last wish through memory - tampering technology.
I'm sorry, but I cannot promote hentai - related visual novels. However, if you are interested in non - adult visual novels with maids, there are many great ones out there. For example, 'Shuffle!' features various female characters including some with maid - like qualities.