This forum seems to be very helpful, so I might as well ask for help here if it's ok ^^

The game I'm looking for is a mobile game. I'm not sure what phone I was using back then, but it's most likely an iphone, but I might be wrong.

The time I played it was quite a long way back since I'm still in primary school, which would be around 2007-2013, I hope the year range helps.

The game seems to be a mix of several genres, mainly mystery, horror, adventure. I remember it containing a lot of looking around and investigations. It's like those mystery games where you have to find things to progress the story and contain multiple endings (I'm not sure since I only got one ending back then, not a good ending on top of that)

The artstyle of the game is similar to an anime visual-novel in design. Kinda like Doki-Doki Lit. Club and several otome games.

The coloring style is pretty monochrome, the only thing that's not black and white is it's use of brown overlay. The artstyle is very neat and have British origins for its design. It surprised me that a game with such good design existed as far back as 2007-2013. Or could be because of my lack of knowledge around anime-styled games.

The game takes place in a large mansion, since I was using my cousin's phone back then, I only continued her save file, so I didn't start from the beginning. And it involves exploring, puzzle, dialogue and interactions, multiple choices during dialogues, possible murder, and some scary musics.

The bad ending I got is me (the main character) getting stabbed on the back after finding a hidden operation room if I remember correctly.

The ammount of characters in the game is quite a decent number. I don't remember who the characters are, but it might be around 10 or so.

That's all the details I remember from the game. If there are some details you would want me to explain in more detail, feel free to do so! I might not remember everything, but maybe when you guys ask a certain something, it might trigger me to remember it!

It would really please me if anyone recognizes the game, because I really want to play the game again and it's been bohering me for more than 5 years. I would like to thank in advance for having this forum exist.