Yeah, I know that the PC Engine version was the one which was the remake of Snatcher that Kojima and crew worked on (with the SEGA CD port being done by a very small team at Konami), which originally released on PC88 and MSX2 platforms. It's funny that they made PSX and Saturn versions that both would have probably sold much better in English territories but left them in Japan and created the SEGA CD version when that system was not the best choice for it, imo. But I do like the SEGA CD version the most regardless.
RE1 Remake charted far higher than RE4 on the same list, though. It appears as though Japan much prefers classic RE to action RE.