Hi,
Interesting question! Quite honestly, I have no idea, I have never attempted to run any of our stuff on Windows 98.
While we do include "Win32" builds with CharPad/SpritePad it is really no guarantee of it working on an old OS, what they called "Win32" or "Windows API" back then is probably quite different to what it is now on Windows 10/11.
For instance, Windows 98 did not feature any support for Unicode strings and the Windows graphics library we use for 2D (GDI+) probably didn't exist back then either.
I would quite like to have a functional Windows 98 or Windows XP machine myself for testing purposes but these OSes won't even install on a modern motherboard/CPU (ie. no hardware drivers available, no UEFI, no 64-bit etc).
It's a complicated problem with probably 100's of reasons why it won't work, couple that with trying to do it virtually using a Mac and it really is a recipe for a headache!
I would be very interested to know if you have any success but my instinct says "no", not without a complete rewrite/rebuild using a very old PC.