The only reason it wasn't released outside of Japan was because it was too amazing.
This game is seen as one of the tougher RPGs, the final area being one of the hardest areas in RPG history. But still, despite the difficulty, it is very worthwhile. It is fun, is simple to get the hang of, has great graphics (despite being for an 8-Bit system), and has an amazing soundtarck (how many series do you know have only three games, bit still gets several CDs, and songs that actually envokes your emotions?), an amazing storyline, and is very fun.
Though it was never released in America (or anywhere else outside of Japan, for that matter), there are beta copies of it that were made for the NES, but were never released, due to the coming of the SNES, and the only way to play it is to get the ROM of it and an NES emulator. And, yes, I have the ROM, that's how I wrote this review. And, you can't blame me: if Nintendo won't give it to us, we gotta go get it for ourselves.
Overall, it's kinda difficult, yet fun, has great graphics, rocking music, emotional moments, a good storyline, and much more. If it ever gets released, go get it.