As far as I’ve played, likely the peak of the NES/Famicom generation in its presentation, from enemy design to how the openness of its world presents itself.

It already has the early stages of Earthbound’s audacious design and storytelling sensibilities, which in some ways is even more impressive when you consider its generation. The developers were certainly unafraid to make quirky choices - my favorite is how they give you an absurdly powerful party member to replace your weakest one for the final dungeon, only to make you do the dungeon again with your weak party member instead.

Assuming you can handle the random encounters (which are coded very interestingly in themselves - random battles become rarer and rarer the longer you are in a given area) then there are a lot of impressive and surprising delights to be found here.