After a game’s worth of inscrutable cut scenes, it is explained to you, near the end of Terranigma, that you are, essentially, the anti-Christ. Per Quintet you’ve resurrected the world, piece by piece: first the land, then the plants, animals, humans, civilization, technology, and ultimately an evil genius the force of whose ideas throws it all into a dark relief, the anti-paradise envisioned from the beginning by the force pulling your strings.
In Soul Blazer, you’re a hero, descending into the underworld to free trapped souls, who, restored to life and their own devices, will rebuild the world for you, freeing you to press ever downward. In Actraiser, you’re a god, conducting your world building from a palace in the sky above, via an interface that allows you to make plans and carry them out. In Terranigma, you’re a mere patsy, stuck with the same man-on-the-streets perspective throughout. All you can do is talk to townspeople and carry items back and forth, the kind of thing Enix has been doing since Dragon Quest. (“Remember, talk to everyone, because you don’t want to miss an important piece of information!”) The connection between the world’s progress and your actions is pretty tenuous.
Some of the dungeons, though, are worth the slog. The longer the better. The fighting/exploring mechanics don’t go much farther than SNK went with Crystalis in ’89, but that’s pretty far in our estimation, and fortunately we’re easily amused.