Great - if you know what you're getting.
With that said, this is a HARD action/adventure game from 1988 that is definitely not for everyone. In fact, it's definitely not for most people.
For most people, this game is fraught with some very difficult-to-kill monsters (Blue Ironknuckles or Knightbirds, for example), very few hints as to what to do next, and when you die - after Ganon laughs at you - you lose all your collected experience points (but not any gained levels) and start over at the very beginning.
For those of us that played and enjoyed this game back in 1988, this is a challenging 2D dungeon crawl that requires you to think outside the box and try unexpected things to advance the story (like jump through walls or walk on water). It's a great game to kill a few hours on the go, if nothing else.
If you remember this game the first time around and enjoyed it then, you'll enjoy it now. Apart from some slight background squishing the game is pretty much identical. If your first Zelda experience was Ocarina of Time, though, better skip this one, you'll just get frustrated with it.