NEC/Hudson unveiled a new hardware board, codenamed IronMan, in mid 1992 that would replace the aging PC-Engine. During the announcement they showed some tech demos and between them there was a polygonal-based flying shooter game that later was known as Super Star Soldier 3D. However NEC didn’t release the new system that year because the PC-Engine was still quite popular in Japan.
Only with the approaching of new rivals like 3DO, Saturn and Playstation NEC decided to release a successor to its popular platform using as the base the old board showed two years before ( it’s still unknown the difference between the original Iron Man and the final PC-FX ), but Super Star Soldier 3D was never finished. The project is of particular interest because PC-FX never had any polygonal-based game.
Scans from Consoles Plus issue 11 and 19, article by Celine