I'll assume you mean an experience based rpg? The Black onyx is one. Though not an overworld, generic rpg that dragon warrior is, same essential type of leveling system.

Incorrect. Japanese made games were also in existence, and better, before this. This was just one of the first NES titles like this, that doesn't make it a classic, it doesn't make it special, it just makes it an early NES rpg, that the makers put almost no effort into. 

Dragon Warrior. Ah the epic quest to save the princess, prove your worth, and slay the evil Dragon Lord. Perhaps one of the worst RPGs for the NES. It holds a special place in many peoples hearts as being a classic from their childhood, but most likely they just never got the chance to play Final Fantasy, or Crystalis very much.

Depth: 1
Now this game, it is long. Like 20-40 hours long depending on how bad you are at it. Its not long because its an expansive world, filled with many different powerful enemies, dungeons, and cities. Its long because there is only 1 small world map, 3 dungeons, 5 minuscule towns, 1 main castle and 1 short 8 floor end dungeon. How did they manage to make this barely any content last? Why we throw strong monsters at you! But lots of them? No. A total of 38, 40 with the final(only) boss, monsters that all do basically the same thing: attack, sleep, heal, or a combination of those. The way they are stronger? They simply pump massive stats into the monsters in the next area so you HAVE to grind for 3 hours just to buy the next sword, shield or armor you want. On that subject, 7 weapons, 7 armor, and 3 shields? Would it have been so difficult for them to have put some effort into this? They did the bare minimum and threw it out saying "okay, its done.". This game lacks any depth whatsoever. The few NPCs who have anything of value to say are obvious as you have to go off the beaten path to get to them, but they just tell you straight out "go here".

Story: 1
Lets be honest here, there is hardly a story to speak of. You start the game and you're off to kill the Dragon Lord. With hardly any money, and the worst equipment in the kingdom. Seems legit. You wander to a town, get told to go to another town cause ain't nuthin' useful here. You go to that town, get told the same thing. In between theres a few people who say meaningless dribble, and a few who tell you to find the princess(paraphrasing here), find certain items, do certain things. All in all its a dull and lifeless story that consists of find the princess, kill the dragon.

Addictiveness: 2
Back in the day, I only had a handful of games. It was between this, Ultima Exodus, Skate or Die, and some crap I don't remember. This was the winner for the simple fact that it isn't evil like Ultima. This game is not addicting, unless you enjoy killing the exact same enemy for an hour because you cant kill the other enemies in the area yet and you want to be close to the key place. Its about as addicting as running headfirst into a wall.

Sound: 3
Cant remember the exact number of songs, I think it was 8. They were all rather repugnant to the ear however, and the terrible sound effect that go along with are no better. The sound effects themselves aren't terrible, its just that I have to hear them every single time I attack and get hit and it gets very annoying.

Difficulty: 7
The game is quite difficult for 1 main reason:
You only have about 3-4 monsters you can face. Oh sure you can always go back and kill slimes and ghosts, but they wont give you the money for new armor and weapon, and you cant kill the monsters in the next area because they are simply so overpowering they will kill you in 2 hits, until miraculously you level up and buy new armor and a weapon, one level mind you, and you are taking almost no damage and killing them with the quickness. Then its back to the same routine.

Graphics: 8
For an NES game, this actually looked rather good. Well, the game itself looked terrible. Bleeding sprites and tiles, barely any detail or animation, HOWEVER, the enemies were very well done. That's probably what took the majority of the space for this game since God knows it wasn't used for the 5 or 6 maps. Unfortunately, the enemies were all pallet swaps. Although there were 40 enemies, there were only 15 individual enemy pictures. The rest were just flipped, changed in color, or had a weapon/shield added. I suppose it was to be expected, they wanted to pump these things out as cheaply as possible back then, but they could have at least given me something different to stare at for hours on end while I grind on the same enemies again and again.

Overall: 3.6
This games really not worth playing. You likely wont have much fun, and almost certainly wont bother to beat the game once you get half way through and realize that its going to take you another 15 hours just to get strong enough to kill the Dragon Lord. People will always try to put a spin on this, how this game was a pioneer, or a classic, but the fact is it was neither. Games like this had been made before it. Better games. RPGs weren't created in the 1980's, they were just turned into better forms. Except this. This was terrible.

I could see that story being the case if you ever actually did anything. You just jumped from level to level, faced a boss, and moved to the next level. There was no stopping to do anything after the bosses as I remember. I could be incorrect on that, but other then getting a new character I'm pretty sure its just boss-next level

disregard everything i said, as i mistook this for castlevania 3 when i reviewed it. if someone could please delete this, that would be awesome.

Now here is a true classic. While crawling through old Nintendo games, you will find one reoccurring factor: almost every game is a copy/pasted clone of other games and offers nothing in the way of challenge, need for thought, or factors to make you return willingly. While you have a handful here and there worth playing again and again regardless of the low quality graphics and sound, it is sadly rare.

Enter Final Fantasy. Supposedly it was thought the game would be terrible in the sales department because they believed Americans didn't care about RPGs. So they pooled together what I can only imagine were the best coders at the time, created music that while still low quality was excellent, graphics that while looking terrible, STILL managed to show great detail, and an OKAY, but superior to any other NES game, story based upon the age old sure thing of "you're saving the world and everyone else is just gonna stand by and watch".
With this game, they managed to create an instant classic. From the first moment you load the game, you are introduced with a small back story, a beautiful song (aptly named Prelude), and a simple no-non-sense starting menu. New Game. Continue. Message Speed. You only have 1 game, but you only need one game. Begin your quest, and you are greeted by something unheard of on an NES RPG : a character creation menu. Now this might not seem like much today, and really it shouldn't, this should have been a basic thing from the very beginning of RPGs. But back in 1987, this was an amazing feature. Choose your party, create your own difficulty for the game. Each character has their own traits, from the fighter who is just a plain beast on damage, but very expensive, to the black belt who is an average fighter, but free, to the red mage, who is completely useless in every party.

The game throws you out into the middle of a field. You have to choose to be smart and head to town or be Mr big guy and try fighting monsters naked. Overall the game leads you on a path loosely defined, with plenty of text from NPCs to tell you about what's going on, hints on where to go, and even a few on fighting enemies. The entire time you are greeted by a catchy and well made tune that never gets old, to this day I still walk around humming the battle theme in hopes of finding a grey imp on the sidewalk. The player and NPC sprites are terrible, and have the most basic animation that they could have done much better, but the enemies sprites are amazingly detailed for the time. The story is decently long, with a few plot twists thrown in, but overall its pretty basic and uninspiring, yet still better then any other NES games. The game is decently long, very long for actually including a real story unlike dragon warrior, which is "grind enemies for 20 hours till you're strong enough for the next land mass", but once again its a very basic story.  Difficulty is a difficult thing to weigh in this game, as how hard it is will depend directly on what your party is, and some parties will breeze through the first or second half while struggling on the other. Overall however, once you know your characters and enemies well, the game loses any real difficulty. It devolves into the same RPG battle formula of "fire on the grass enemies, lightning on everything in water, and spam attack and everything dies". There are only basic spells, stats have a minute effect on battles, buffs are useless, and  debuffs/shields are only useful in a handful of cases. It all falls into killing 1 enemy over and over because it drops lots of money, running from everything else because it poisons you or is a waste of time, and buying the most expensive stuff to super own every monster in the lands.

Overall, this game is worth playing. For the time it comes from, it showcases the very best around it. It lacks the idiotic attempts at "humor" the rest of the series attempted, the worthless mascot characters who don't ever actually do anything in any of the games, the terrible pop culture that appeared more and more when the Japanese realized we would buy these games, and contained the features that would become a stable in almost all RPGs thereafter.  One of, if not the best game, on the NES, it is worth a play or 50.

Graphics: For being an NES game the graphics are actually rather good. The game has a nice dark atmosphere, well animated characters, and great transitions between the dream monsters and regular monsters.

Sound: The music/sound effects aren't annoying like in almost every NES game. Nothing memorable or special, but by no means one of those games that just makes you want to hit the mute button.

Addictiveness: Well there is none for me. The game lacks any sort of story, the levels are uninspired, and its full of cliché enemies that do nothing but wander back and forth or throw something at you. The difficulty is quite high, while not being the hardest game ever, its merciless. Every enemy takes forever to kill, and you have no manner of health display whatsoever. The bosses are all just boring pieces of Freddy on a chain. The scenes where "Freddy's coming" are terrible, you basically just try to jump over his head and hit him when his back is turned, and repeat this over and over and over. There's nothing here to make me WANT to play this again and again, the only reason I did as a child is because this was one of my few games.

Story: PPPPFFFT. There is no story, no direction, nothing. You just run to the right, jump over enemies and wait for Freddy to come lay the smack down on you.

Depth: While the levels kind of change, they are still the same thing over and over. Jump over spiders, jump on a platform, throw knives at a skeleton because your fist does absolutely nothing.

Difficulty: Oh god. This game is very unforgiving. You WILL die constantly, you will not know when the next hit is going to kill you, and you'll have loads of moments where your punch hits the enemy and does nothing, or your knives, or you wont jump when you press the button. Those are SOME of the bugs in the game, which although they are bugs, contribute greatly to the difficulty.

Overall: Well the average from those scores is about 3.8, but honestly this game is a 1/10. It has nothing to keep you interested, nothing to bring you back, and its full of infuriating bugs and boring monsters.