In the series, The person playing explores mysterious areas, and sees very random things happening, The person playing isn't voiced. They presumably are the one putting out the videos, putting stuff in the descriptions of the videos, and sometimes even interacting with the audience in the comments.
Dark Castle shows examples of the following tropes:
- Random Events Plot Episode 6 is all just random things happening, from cross imagery, to random text, to improper dice.
- Something Completely Different Episodes 1-4 are mostly just the Protagonist exploring strange areas, But in episode 5, it's all just a bunch of text on the screen, something the description calls the "Transcripts", presumably meant to tell a story.