Image provided by: PeterPeter sent me”Knot”which is: (author’s words now:)

This demo uses mode 1 and shows a flatshaded rotating knot with about 250 faces. It uses some fake lighting (triangle z-depth multiplied with some magicnumber used as color) and Z-Sorting. The glow at the bottom is achieved with an alphablended object. The 3D object is rendered first into an offscreen buffer, gets then converted into a tileset and directly stored in videoram. Everything is written in C. Hold -A- button for some special fx, heh. Tested with no$gba and on hardware.

http://www.console-dev.de/demos/index.html