The reason you played the first game

[Lone Wolf Leonhart]

This game is too unfair, unreasonable, unforgiving, annoying, and the battles take forever. I've just acquired the mystic key - does this game ever speed up, or is it a constant struggle all the way through?

Later versions of the game (PS1, GBA, etc) are either easier or have an easier mode. Something like that.

From what I understand, the original NES versions of Final Fantasy games tend to be harder than their ports for one reason or another.