OK, first off, the gamepay is hardly affected, you are just watching a different story. I must say, Nintendo did a fine job in connecting these games in plot and so on. If only they could've completed their origninal goal: 3 game linking (They had to cut it down to 2, thus, Farore was demoted to a desk job, but it makes you wonder, if she did have her own game, whoudl she still be oracle of secrets?).
Still, this is a fine example of a great hand held game. One problem though, not much re-play-ability. Which, now that I think of it, true for most RPG's, so I won't count that against it.
Back to my point, the differences; Zelda chills with Impa, and fully restores your health, until she's swept away by bitch and bitch's sister *wait, what? its witch? oh, my bad......
Anyway, the sisters appear numerous times, they actually are the first thing you see when you start the second game, plus they make numerous more "appearences". I've talked to Jaetei, and he says that the scene where you rescue Nayru is so very much cooler than in the 'un-linked' version.
You eventualy fight them uppon completion of the 8th dungeon, and, just as in OoT, they form twinrova, but how you beat her is different. When you finnaly fight ganon though, he's back and uglier than before. His moves are awesome, armed with a big trident (no, not the gum) and a hell of a lot of guerdo magic he makes one big pain-in-the-ass of a boss.
Can't tell you what the ending is though, cause that would set off a chain reaction of events resulting in nintendo not making as much money, and heaven forbid.....