I feel like I've asked this question before, but I couldn't find it in a search. Needless to say, if you haven't finished Link's Awakening, you should probably stop reading NOW.
I let the official Nintendo Player's Guide to The Legend of Zelda: Link's Awakening spoil me utterly and completely for the game, and if I had to do it over, I would refrain from doing so. But there are a couple of points that are just obscure enough I have to wonder if anyone here completed the game without any hints.
Namely, there's a statue in Turtle Rock that you're supposed to fire an arrow at to get a small key. Except there's hundreds of statues in the game that look just like it, none of which respond to you in the slightest, nor is there any suggestion that this statue is different. And of course the bow is actually optional before that point.
Somewhat less obscure is the whole deal of finishing the trading quest and going to the library and applying the path from the book to when you get to the Egg, though the book does at least suggest what you're supposed to do with it, and once you get the Magnifying Glass, you can probably figure out that you need it for the book.
So did you finish the game independently without any help when you played it?