I still don't think you understand the consequences of the Neo Geo's CPU and VDP not sharing any RAM.
I think that demo actually builds the cube out of tiny sprites. That's the impression that I got reading the bouncing text, anyway. But even if that's the case, chances are that virtually all of the system's sprite bandwidth and a great deal of its CPU power are being soaked up just trying to build that one simple cube.
Oh and if you want to program 3D on the Neo Geo, it can be done again with TRICKS, always a way.
No there is not. There is sometimes a way, and in this case the prospects for the Neo Geo doing any kind of graphics processing that is directly assisted by the CPU is extremely bleak. It doesn't matter how powerful the CPU is if it and the VDP can't see each other.
If the CPU could see the VDP then the Neo Geo could indeed provide some serious polygons. The easiest way would to be adding RAM to a cart then you'd have something special. But then having an arcade stick layout stinks for 3d style games except maybe a fighter like virtual fighter.
I doubt that cube is taxing anything, just a simple proof of concept.
Who the hell wants crappy "I'm barely capable of this" polygons anyway when you can have an easily animated 2D Earthquake?
I don't think Stunt Race FX caused any envy in the Neo scene...did it?
I just got Stunt Race FX, it's a slide show. Still fun however but man it's like playing Doom on a 386.