> Is it not emulated in Mame because it is still sold?
Yes.
> I'm sure it's been emulated already but made not to work in Mame unless you're in the know.
MAMEdev is the most transparent organization on the planet; everything we do appears immediately to the public in GitHub. Your fantasy greatly overstates the amount of effort anyone would go to for a game which is barely interactive and which works just fine in Daphne.