Coming from an ArsTechnica interview with Dylan Cuthbert...
On why X (Game Boy title) wasn't released stateside
I think the problem was that the retailers in America didn’t really want to pick it up—it was an advanced 3D game, and they wanted simple puzzle-like games, which of course were selling like hot cakes. The Game Boy wasn’t really an experimental market, and the user base didn’t really need 3D to enjoy the machine. So our game was just a little too nerdy for the market climate at the time.
On the size of the StarFox team
The team was pretty small, with just three programmers, so no single one of us was "lead" as such; we just led different aspects of the programming as needed, switching roles on the fly.
On if he has any insight into how StarFox 2's ROM leaked
No idea. I’ve only ever had my hands on the final QA’d ROM, which we had a good play with before making Star Fox Command. I seem to remember an even older ROM being leaked from CES—back in those days, security wasn’t the tightest!