The readme give detail on how to set up and play using two pads. I have gotten the two joypads style to work using the Sidewinder and a PSX controller but that's rather awkward. I want to play it using Saturn style controls, using one gamepad but it won't let me. Is VO maybe looking for a non-USB Sidewinder?
As for Sega Pad & TwinStick, it might be possible that it's referring to some PC video/game card that let you plug in Saturn controls into it. I don't remember what card it was though, just something from years back.
Here's something I found.
Diamond EDGE �3D PCI
Diamond Multimedia EDGE 3D 3400XL - NVidia NV1
Another sidenote, this is probably knowledgeable already but still neat. If you place the Saturn VO disc into the comp cd player the PC VO game will play the cd audiotracks correctly, similar to PC Quake demo playing correct cd audio off of a Saturn Quake disc.