It might be. The idea of'soul slayer' could easily fit into a horror theme. Slaying souls sounds like a rather dark and spooky concept, so there's a good chance it has horror elements.
It stands out because of Markiplier's influence. His brand and style bring a unique touch to it. Compared to some other horror visual novels, it might have a more energetic and engaging presentation.
It might use spooky visuals. For example, dark and shadowy scenes in the visual novel can immediately set a scary mood. The art could depict things like old, decrepit buildings or strange, menacing figures.
One similar horror visual novel could be 'The Witch's House'. It has a very spooky atmosphere and a strong narrative, much like what you might expect from an 'aquarium horror visual novel'. Another is 'Mad Father', which is also filled with horror elements and a sense of dread throughout the story.
In a regular horror visual novel, the plot is centered around scaring the player, perhaps through jump scares, psychological horror or a build - up of a menacing atmosphere. But in an 'erotic horror visual novel', there can be complex relationships between characters that involve sexual undertones or desires. These relationships are not just for the sake of romance but are deeply connected to the horror aspect. For example, a character's sexual obsession might lead to a series of horror - filled events or the horror might be expressed through sexualized violence or threats in the 'erotic horror' genre, which is not typical in regular horror visual novels.
Cosmic horror visual novels often focus on the vastness and incomprehensibility of the universe. For example, in a normal horror visual novel, the threat might be a serial killer or a haunted house. But in a cosmic horror one, it could be an ancient and powerful entity from another dimension that defies human understanding. So, the source of horror is much more abstract and far - reaching in cosmic horror visual novels.
I'm not sure specifically as there could be many horror games or visual novels with 'the letter' in the title. It might be about a spooky story that revolves around a letter. Maybe the letter contains a curse or some dark secret that sets off a series of terrifying events in the game or story.
Here are some recommended visual novel suspense horror games:
1. [Limit Escape 1+2 and 3: This is a suspense visual novel game series.]
2. AI Dream Detective 2: This is a suspense visual novel game.
3. This is a Suspense-Based Visual Fictional Game.
4. Reversal Judge, Great Reversal Judge, Reversal Detective: This was a series of visual novel games that used several games to deduce and solve cases.
5. Night of Horror 1: This is a horror suspense visual novel game.
6. The other side of the mountain was a Japanese mystery mystery game.
7. Under the Abyss, Truth Forever: This was a suspense novel that combined the elements of a horror game and a female protagonist.
I hope these recommendations can satisfy your needs for visual novels and suspense horror games.