Okay, so. I'm horrible at explaining things, but what they are talking about is the channel
Doukutsu Iterations, who- in character- posts gameplay videos of a seemingly modified version of Cave Story that "generates" what are called "iterations" of the game using some kind of AI.
These videos come from different time frames, from early 2008 (Video
black_fog, an iteration 1 video apparently recorded on Nov. 8 2008) to all the way up to now (Closest to now, at least, is video
i6_20240530_09, which according to the title/filename, was recorded on May 30 2024). The channel's videos also take heavy influence from Pre-Reset Cave Story, which is what iterations 1 and 2 are based on.
Obviously it's very much like Petscop, what with it appearing out of nowhere, using a game engine (in this case, the Cave Story engine, probably CSE2-accurate?) to tell a rough, deliberately vague story. The in-universe owner of the channel
is a Mimiga, after all. Probably from one of the "iterations". It's not an ARG, like how "wackodude47_and
kunckles" [sic] is saying it is.