Helpfully, some of the staff of the Saturn version saw fit to leave some messages on the disc about the development of the game! Translations can be found here: https://tcrf.net/Aku...oukyoku_(Saturn)/Developer_Notes
I get the impression that, as with many Playstation to Saturn ports, they had a small budget, little time, and no familiarity with the Saturn. Even ignoring the resolution issues, the end results could have been a lot better; it feels in a lot of instances like they were trying to force the Saturn to do things like a Playstation, rather than retooling the game to use the Saturn's strengths. As stated in the DF Retro video, a greater use of the VDP2 would have gone a long way. Like, did the swirling vortex in the background of the Richter-Dracula fight need to be 3D? A similar effect could have been produced using the VDP2's Mode7-like background layer, freeing up cycles on the VDP1 to allow full speed gameplay. Of course, this would have taken more time and budget to do, so, we got what we got.
^The cutting Room Floor Link is broken(it cuts off the target url before the ) at the end of Saturn.
Though correct me if I'm wrong, but wasn't the PS1 a, for the times, 3D powerhouse with no 2D capabilities while the Saturn was a 2-D powerhouse with very weak 3D hardware? Such that all the 'sprites' in the PS1 version of SotN are actually flat polygonal models? I know every little about computer graphics, but I can't imagine a 2-D game that was originally rendered entirely with 3-D would do well going to a system with weaker 3D hardware, nor would I think it trivial to convert flatten 3D models to true sprites.
That said, I've only ever played the PSP version unlockable in Dracula X Chronicles, which I believe emulates the PS1 version.