The story, from my recollection, is more based on a human's observations of the Flatland world than anything else.

Pretty boring (like much of Hinton's writing), and not much in the way of math. Actually, this was the least boring of all of Hinton's fiction that I've read. Some of the characters believe that they can save their planet from disaster by using the 3rd dimension, but how they would accomplish this in practice is not revealed in the narrative. No 3D creatures come to save them... the text ends with nothing resolved.

Just to let you know - I have a complete version of Hinton's An Episode of Flatland on my web site, not the abridged version found on most sites.

I'm also the author of a Flatland Role Playing Game published in PDF and sold in aid of Doctors Without Borders. Any publicity you feel able to give it would be appreciated.