I beat it pre-internet with Nintendo Power, I think. It was tough, but I liked it -- and still do. The one thing I will say about Zelda 2 is that the difficulty curve is kind of wonky. It starts out challenging, gets very hard very fast, then eases out for a bit after Death Mountain but continues to get even harder. I think it's a great game, and I wouldn't mind seeing a new platformer Zelda, but I do not prefer it to the original. My tips would be to get good at jump-slashing darknuts in the face, that takes them down easy. Also, avoid enemies you don't have to fight and can get away from, to preserve your health. Don't be afraid to use spells like shield for a challenging room of normal enemies, since the game is pretty generous with magic jars (I had the habit of never using magic unless I had to, which was a mistake). Always leave magic for the Life spell. Grinding for levels does help a bit but is only worth doing at certain points in the game: it's more important to get the container upgrades.
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Every jumbled pile of person has a thinking part that wonders what the part that isn't thinking isn't thinking of