David Broadhurst (The talented Programmer.) had quite a few problems in the
creation of Ghouls N Ghosts.
He began his computer career on the ZX81 ! and later upgraded to the good old
Commodore 64 producing games like Mr Frostie And The Killer Penguins and 
C5 Clive.
He then got a job with Software Creations and has produced Bubble Bobble, LED 
Storm, Bionic Commandos and Ghouls N Ghosts on the Amiga.
They started doing the arcade conversion by testing Ghouls N Ghosts over 3 
weeks and the first thing for David to undertake was the scrolling.
The arcade had 3 levels of parallax scrolling, but David made it just the one, 
this gave more memory for other areas, such as more detailed graphics.
The Arther character in the game used a flipping routine, this also allowed
less memory to be used. For an example, the left sprite image was flipped
giving the right image sprite, so only the left animation sprites needed to be
drawn. "The sprite routines are simple, but the sprite logic was difficult,
mainly because there was so much of it. Every level was essentially a separate