When Igarashi took the reins of the Castlevania series, one of the team's primary goals was to increase the amount of time that players would spend with the game. Several options were considered, including adjusting the difficulty or changing the ending of the game to promote multiple plays. In the end, the team decided to increase the amount of exploration.
"We really wanted to extend the life of the game," said Igarashi, "and the one game that popped up in our heads was Legend of Zelda, an exploration-filled action game. Pretty much our entire team, including myself, were huge fans of the game, and we wanted to make something very similar. So now you know the origin of inspiration actually wasn't Metroid."
Even so, Igarashi is happy that his Castlevania games are associated with Metroid, although he didn't actually learn of the term "Metroidvania" until around two years ago, when he noticed fans posting about it on Facebook. "I like the name and I respect it," said Igarashi, "and I like the meaning behind it. It fits very well, so I'm actually kind of honored that Metroid, the name, is attached to Castlevania, and that it morphed into this one word, so I like it very much."
Of course, back in the late 1990s when Igarashi and his team were creating Castlevania: Symphony of the Night – the game that established today's familiar formula – the term Metroidvania didn't exist. So, what did they call it? As Igarashi told us during the Q&A session, it wasn't very flashy. "We didn't really have a code name for it. It was very basic and plain and we just called it '2D exploration action game.' There was really nothing special about it, so there you go."
Another panel attendee asked about Symphony of the Night's famous inverted castle, and what inspired its creation. As it turns out, said Igarashi, it was just easier than creating new monsters and assets.