The predecessor to
Earthbound. After people played and loved the US
Earthbound, they heard it was actually
Mother 2 in Japan. This meant there was one before it.
Thus, some people got hold of the old one (Mother), translated it, localized it as much as they could, and released the ROM as Earthbound Zero. (Given that Earthbound 1 is what we have, it's predecessor would be Earthbound Zero)
The game is hard. Very hard. Enough said. I still haven't gotten to the second party member yet. But at least it has the same music for fighting New Age Retro Hippies. Word to your old-school console RPGs.