Hey! It seems that both the GB and GBC versions run fine on a regular GB (DMG), so I'm a little confused as to why there are two different versions? The GBC version and the GB version look identical to me when running on a GB.
However, the GB version doesn't seem to work on a GBC - after the initial fade, the screen remains black, so there seem to be some palette issues there. But, again, I'm not sure what the GB version is really for, since the GBC version runs on a GB.
(The reason I wanted to try the GB version on a GBC was to play around with different palettes, so that could be one reason for its existence!)