not sure if anyone here is interested in unfiction stories or ARGs, but I stumbled on this Cave Story-based YouTube series a few days ago (both the videos and the community/posts tab contain story elements).
it's a bit early going, and it dosn't seem like its creator has really settled on much of a "direction" yet, but it's premise seems interesting enough to take a look.
my take on the story; minor spoilers
it seems to be another go at the ghost in the machine (sentient AI) trope. with some unknown character/group developing and testing player AI and level generation algorithms using Cave Story as an environment (for some reason).
although this story comes at it from the angle of our host character (610) seemingly being one of the "ghost"s, rather than a third party (or just the antagonist) like these series usually get.