While browsing the Widescreen Hacks of Esppiral on his Discord forum, I discovered a Technical Demo of Yu Suzuki dating from 1998 proposed a few years ago thanks to the forum Assembler Games : Tower of Babel.
On the other hand, I did not manage to find a functional .CDI version (the GDI version arrived on a Debug menu where we could not launch the demo).
Most were talking about running it from a devkit to get it to work.
After looking for a bit, I offer you this technical demo in .CDI version (so you can play it from a real Dreamcast)

As a bonus, I gave you the 2 versions : the normal and the widescreen hack

Thanks to Esppiral for the Widescreen Hack

A video from The Dreamcast Junkyard :
https://youtu.be/QKVMKO3rfb4
Edit: after testing on GDEmu, unfortunately it does not work. So only on Emulator