dtgreene: Fortunately, it's easy to change to the retro soundtrack when you enter the area where that track plays; that's one of the neat things about the remake. All it takes to change to retro graphics or sound (or change back) is the press of a button (or key if you're using a keyboard).
ResidentLeever: Yup, definitely a nice feature. I was hoping for some level design changes and extra areas or bosses for the remake so I haven't played it yet, but I probably will soon.
The remake has new challenge areas, one for each form, hidden in various spots in the game. No newe bosses, however.
There's also a hard mode. If you've played Wonder Boy 2, you might remember that there was an hourglass, and when it emptied, you would take damage. Well, the remake's hard mode adds it to Wonder Boy 3.
By the way, tinahacks is running this game at AGDQ, which is this coming week. (Speaking of which, some people on this forum might also be interested in squibbons's run of Ultima 6 (SNES version), also at AGDQ.)
Anyway, when I mentioned good Zelda music, there was one major ommission: from Majora's Mask (which I *have* played, unlike the other examples I gave earlier): Stone Tower Temple. That's one of my favorite pieces of video game music of all time.