I'm sceptical about any commercial title having NTSC and PAL versions, however RTG games could work equally well on both.
Another issue that I'm surprised wasn't mentioned is the aspect ratio: often games ported from the PC have 200 lines and so will look better in a real NTSC mode, and hopefully play better, too. Whereas original Amiga titles are more likely to exceed 200 lines and look funny in NTSC even if there's nothing missing at the bottom/top. So a part of the question is, in what environment did the artist, or whoever made the end result graphics, work in?
