Yeah that's rushing a bit. To shave it down that much you'd have to go straight to each item/goal and not bother with any of the optional stuff. That doesn't seem fun to me.
Like I said, I looked a couple of things up because figuring out the pattern was getting tedious, but I didn't really get in any hurry. I'd say I spent about 12 hours or so on it, a few each night, but because I got lost and explored a bit, it would be more reasonable for someone to spend 8-10 if they've played the original and already know a few of the more cumbersome solutions.
I spent a few more hours tonight going back and searching for some of the optional stuff.... There are more seashells and hearts than were originally in the game. I'm not sure why extra hearts were added as they really aren't needed, especially with the three added fairy bottles, but I guess modern gamers are really bad at the old stuff or something.
The extra seashells are psuedo useful:
Getting up to 40 will give you the island's sword, which is essentially the master sword. Double damage and shoots a beam when your hearts are full. 50 (which I haven't gotten yet) gives your a modifier chamber for the build a dungeon. It's supposed to makes rupees fall from the sky, which would be useful earlier in the game but is completely pointless by the time you are able to get all 50 shells. I got all the prizes from the claw machine, that took about 15 minutes.
I've got several heart pieces left to get, but it's getting less fun with every trip.... probably time to put it away.
The go to prize for collecting all the extra stuff are chamber stones for the create a dungeon which will add special rooms. So far it's really nothing fun added.