Can you also fix the wrong map piece? http://shrines.rpgclassics.com/sms/golvellius/extras.shtml
"Flaw in Crawky Map. Someone must have been a little tired while creating the maps. Take a look at the middle of Crawky Forest in the Maps section. The picture at the right shows a closeup of one screen area that was drawn in the wrong place. It looks like the farthest NE corner of Crawky Forest was used twice (once in the NE and once in the middle). You can see how the river stops and starts again past this square. The trees are cut in a perfect line and the mountains end in a perfect line as well. The Japanese version of the game contains the correct map piece in this section."
Also, this is personal opinion, but I think the sms version would greatly benefit from more open paths instead of so many dead ends and walk arounds. So much time is wasted walking.
All in all, I think the biggest problem with the game
is that every single hole looks the same and that becomes a problem when you're looking for that hole that contains a crystal when you defeated a boss. There's no way anyone can remember which one it was, so at the end of the game it becomes a guessing game or you need to systematically go through every hole in the game to make sure you get all crystals. So, I would mark each crystal hole with a different graphic on the overworld, or ideally mark every hole with content identifiers (old lady, fairy, dungeon, crystal, health refill, etc).
edit: oh, the bugfix is the misplaced map piece?