The first of it's kind, The Legend of Zelda is a highly addicting game were you are confronted with numerous puzzles.
The Good: Challenging riddles, Unique boss fights, Classic adventure story, one of the only NES games that you can save.
The Bad: Large map is hard to remember were anything is, Few save points.
As you progress through the game you come across better items that allow you to overcome stronger bosses and fight different monsters more easily.
The combat is difficult, but entertaining. You also have to really think when confronted with a difficult riddle or puzzle. Often ending in frustration ; though the reward is worth while. All the dungeons are unique and present different monsters that compliment their surroundings and have different way to defeat them. Though Zelda isn' to much about the fighting as it is the puzzles and riddles.
As for the graphics their what you should expect from an NES game, but are instantly classic, and grow on you. If you are already a Zelda fan then this game will give you one fun filled adventure, and a look at Link when he was first created. The best fights are the boss fights. Each one is totally unique from the other and take awhile to grasp sometimes, but are entertaining and challenging.
The most angering aspect of this game would be it's scale. You didn't have a map so you have to rely on memory for the whole game unless you either sketch out the map or find a picture of it online. You also get hit by many monsters while looking for the next dungeon, and sometimes enter a new dungeon with hardly any health.