Not sure about a PCE HuCard version, but a PCE SCD version could've looked closer in terms of color and background detail (minus parallax) than the MegaCD version, which lost ALOT of color and SOME graphic detail. As Black Tiger mentioned, MegaCD version is redrawn. It's only a rendition of the arcade, with less detail, not a pixel-exact port.
Of course, the X68000 version lost zero color or detail, and truly *looks* pixel-exact to the arcade ^__^
MegaCD|SegaCD vs Arcade SFC|SNES vs ArcadeGBAX68000 vs Arcade99.9% of people (nearly everyone) believed that the MegaCD-SegaCD version of Final Fight was arcade-exact, or damn close to it, and thus, it was the closest home version during the 1990s, until Capcom Classics Collection in recent years. That's because all they knew of in the 90s were the two SFC-SNES versions (FF and FFGuy). So in comparison, the MegaCD-SegaCD version *seemed* perfect compared to the Nintendo versions. Almost nobody had ever heard of the Sharp X68000. Even most people that knew about the obscure Japan-only SuperGrafx, did not know about the even lesser-known X68000. It just did not exist to people.
Anyway, the MegaCD-SegaCD version of Final Fight was certainly the best home *console* version of Final Fight. It retained all of the features of the arcade (all levels, all selectable characters, 2-player play), and on top of that it featured superior music and an exclusive animated intro that no other version, not even the arcade, had. Like so many other things in life, all of this combined to BLIND most people into thinking the MegaCD-SegaCD version was more exact to the arcade than it really was. Indeed it was an outstanding rendition of Final Fight, the best that could be bought domestically in the United States, and even those in Japan who did not own a X68000.
Compared to IBM PCs and even Amigas, the X68000 was the Neo-Geo of home computers. Thank God the games didn't cost $200~$300. It's just the hardware that was expensive, much more so than the Neo-Geo itself. I think a X68000 cost $1000 to $1500 at least, in the range of a LaserActive. I could be off by a few hundreds bucks, but does it matter, at THAT kind of cost? I think no.
To be clear, the X68000 Final Fight wasn't 100% exact in every way, it did not put as many enemies on-screen as the arcade, I think only 5-6 at most, instead of the arcade's 7-8, but still more than SFC-SNES's 3 and MegaCD-Sega's 4.
Anyway.... The creators of the PC-Engine family of hardware, Hudson, did contribute to the design of the Sharp X68000, at least it's OS, and perhaps (not confirmed) maybe its graphic chip(s) also.
If (oh man, IF!) NEC & Hudson had ever come up with a true 16-bit PC-Engine 2 (say in 1990 or 1991), rather than the modestly upgraded 8-bit SuperGrafx of 1989, I would've hoped for X68000-quality results. The PCE/TG family would've become legendary, in the same sense as the Neo-Geo did.
I wish there had been a X68000 version of Forgotten Worlds. I'm sure it would've been almost-exact, in the same sense that X68K Ghouls 'N Ghosts, Strider, Final Fight and SF2CE were.
The X68000 is very much what I had wished the SuperGrafx (or PC Engine 2) had been.