I know this is a decade-old argument, but I only just now got around to playing it. I'm through 2 palaces so far, and I honestly think this game is very underrated. I'm also playing A Link Between Worlds right now which is a great game, but I feel as though I have to force myself to play through it. It is far too easy, and the puzzles feel too predictable. But Zelda II on the other hand -- I can't just "put in the time" to complete it. I actually have to make an effort, learn enemy attack patterns, and pay attention to NPCs. In A Link Between Worlds, completing an objective feels simply like a job well done, but in AoL, completing an objective feels like a huge victory. Do any other TCP'ers feel this way too?
PS: This post isn't intended to criticize ALBW. It is an excellent game, but I suppose after beating enough Zeldas, the classic formula is very predictable.
EDIT: So I just completed the game. The Great Palace was obviously very difficult. To be perfectly honest, I used a guide for the last 1/3rd of it (not really out of necessity -- I just really wasn't in the mood for the hardcore process of elimination). What surprised me is that I have always heard "Thunderbird is ridiculously hard. Etc etc." But I actually found Thunderbird very easy. Obviously you can die easily if you're being stupid, but some basic dodging and it's a breeze. I also was expecting Dark Link to be near impossible without the corner trick. I had an extra life, so I decided to try it legit first. I went into the fight with only 2 bars of health. I got Dark Link down to half health before dying. I ended up just using the corner trick on the next life, because I was exhausted, but imo Dark Link doesn't do enough damage to outlast you. My biggest complaint about the game is the excessive random overworld fights. Other than that, it's a great game.
EDIT 2: I am surprised at the amount of people who have to use save-states and crap to beat this game. Obviously it was hard, but damn people just suck at video games these days.