I noticed in the title screen there is already a graphical glitch.
In a dungeon shop in the uppermost and somewhat right section there were two invisible items for sale, both priced at 70 gold, both unbuyable.
In another shop the mother's wings are sold twice, the price is D0 gold each; that surely is more than one can accumulate.
I soon got aware that the old dungeon architecture is pretty much still intact. The changes were merely done within the rooms, as if furniture had been moved around. It mostly results in the removal of auxiliary structures so that some places early on will be too high to reach for the unsuited characters. The original was more ambiguous as to who belongs where.
The macro routes through the dungeon remain the same, and that's the biggest disappointment.
I got excited because I expected a whole new adventure, but now I'm uncertain if it would hold my interest.
I played through LotW in 2010, and to me it was the better Metroid. I loved the amazingly smart exploration aspect and the puzzle-heavy father's segment.
If I decided to replay it I would probably choose this hack or the MSX2 version. But with these few changes I'd rather still wait until I renew the experience.