For one, the re-translation has been skewed quite young. Gone is the Elizabethan English dialog, and the game just doesn't feel the same without a gratuitous 'thee' or 'thou' thrown in. And those who remember the cameo appearance of Nintendo's Nester in their first voyage will search in vain for the character in this new quest. Graphically, Enix did very nice things with the visuals in this game. Compared to the chunky old NES versions, the monsters virtually pop off the screen, and the towns flourish with life.
Landmarks are much more clear, and even the main map is more impressive.
All of this was crucial for this game, since the smaller size of the Game Boy screen cuts the viewing distance almost by half. If the world wasn't memorable visually, players would be instantly lost in the bland kingdom. Still, more should have been done with the game. Chiefly, improvements direly needed in Dragon Warrior II were skipped. You would think that at least there would be new sights to see at a given turn, but instead it's all dull black.