This is a historically important game. But is it a great game that should be revisited? That's up for debate.
For the NES, the visuals are bright, the music is fantastic, and they do their best to make it epic. The physical box came with a massive 84 page manual and foldout charts with a world map, and listings of magic, armor, weapons, and foes. The sparking of imagination this provoked in me as a kid cannot be overstated.
The original release has more than a few bugs and the difficulty can slide towards 1st edition D&D unforgiving at times; especially if you're averse to grinding. Because there will be level grinding done if you want to see the end of this game. That said, the bones of a sprawling franchise were here from the start. And that can be more than worth checking out.