Yerbity Flerbity.
I never had a lot of exposure to MZX games of the 90s being too much of a baby to know what "conventional memory" meant. This feels like something that would show up on a ZZT Sunday stream of something from the AOL days.
When I heard this game had ties to Magic Quest and that people were missing out on something about it, I assumed that it was something too well hidden. But you named somebody gmail.com and I think that should clue people in. Given what little else is there, I'm surprised people took awhile to notice, such is the challenge of setting up an ARG I guess.
Like <s>Internet Explorer</s> Edge being the web browser of choice to download Firefox with, Yum Yum Town is a great way to find a zip file's password.
Love the name Yum Yum town too.