The X68000 version the only version that's truly arcade perfect. Not even the Capcom Generations / Capcom Classic Collection versions are as perfect, because of small problems
Sorry this is so large but I thought it would be nice for you guys to see the back of the X68K GnG box:
http://h12.abload.de/img/daimakaimura_x68000_b8duhh.jpg
(Huge pic changed to a link -Ghegs)
mini-review
http://www.illusionware.it/x68000/gng-x68.htmReview - "3 years later, the land was seized with nightmare again. Arthur took up arms for the fight for justice. That was 3 years before when Arthur the Knight brought peace into the land. The struggle against the Prince of Evil seemed to come to a dead end and people hoped to live in peace and quiet for good. Yes, they had hoped the peace to be ever lasting until it happened..."
The x68000 version of Ghouls'n Ghosts is supposed to be so good as to literally eclipse the Mega Drive and the SuperGrafx versions.
Everything apparently looks and feels arcade perfect from the color palette to the graphical definition of the sprites and the backgrounds. The only annoying thing about this version is that it runs on disks although it should be possible to install the game on Hard Drive. What really sets this version aside from the others is the deluxe packaging that is by itself, worth of the purchase!
On a side note, it is interesting to notice that the red text to the upper left side of the box (which I quote at the beginning of the review) refers to Arthur bringing peace to the land 3 years before. Indeed, it was 1985 when Ghosts'n'Goblins came out, and Ghouls'n Ghosts showed up in the arcades in 1988.
Well to be honest, I don't know many people who played Ghosts'n Goblins and who were actually able to finish it because of the near to impossible difficulty of the last stages. So I guess it's no wonder Evil returned shortly after
Bottom line: an astonishing port of the original arcade pcb which only fault by today's standards is to run on disks. 9/10
Comparison of the 16-Bit versions:
Arcade CPS1

MD/Genesis

SuperGrafx

X68000

Notice the X68000 version is the only one here that has the detail & color of the arcade. The Capcom Generation / Capcom Classics Collection versions have all the detail & color too, but they have their little problems like different resolution and dim parallax backgrounds.
Note: This discussion does NOT include Super Ghouls 'N Ghosts because that was the 3rd game in the series.