Psychic powers and bottle rockets. Zombie-leading puke and cults of blue. Scratch-and-sniff advertisements and phoning home to save.
Of the many, many things that can be said about Earthbound, 'typical' is not one of them. "Cult hit" would be more accurate, and "definitive cult hit" wouldn't be too generous either. Other words often thrown around are "fun," "super-mega-fun," and "Steve Johannsen, I'm coming for your soul."
This cult status brings with it a rare quality, one which manifests differently depending on the game (and player), but is evidenced through uncommon affection or reverence by the gamer. The game is simply held in higher esteem - not because of a lack of commercial success, but because of perceived quality in spite of that. Such games are the underdogs, the underappreciated, the games few people played but everybody loved.
This, of course, is the case with Earthbound, which earns its endearment largely through an oddball sense of humor. Although the core mechanics of the RPG are intact, the entirety of the game comes out vastly different than most other RPGs out there. The game is, quite simply, weird. The heroes aren't children elevated to adulthood by ageism and circumstance, they really are children. Children with superpowers and firecrackers. People want to turn the world blue. Zombies really are eating your neighbors. And that's not even the half of it.
It should go without saying, however, that quirkiness - that same quality that makes Earthbound truly unique - is almost duty-bound to doom a game in terms of mainstream success. The very word, quirky, implies something not normal, not the status quo; truly, if everyone were doing it, it wouldn't be quirky, it'd be run-of-the-mill. Such oddities can certainly succeed, but they themselves tend to be the exception, the minority of the minority.
As is true with cults (especially cults of blue), so must be true of cult games. They have to be rare. They require a degree of scarcity. For such games to become the norm is to potentially rob them of their novelty. Earthbounds 2, 5 and 10 might have been solid, excellent RPGs that sold by the millions.
But I still wouldn't trade Earthbound 1 for them.
Consider this not an endorsement of cult games over those with more mass appeal as a general rule; that would just be naive. Instead, consider this a reminder that the industry needs both, even if they can't exist together in one series.