Yes, I started out by comparing the concept to Zelda 2 a long time ago, and people revolted. Which, by the way, is not an RPG -- it's a sidescrolling adventure game. But people don't really know what that means, most of the time. If you're excluding actual Metroid and Castlevania games from the Metroidvania genre, I think there's not a lot I can say to convince you: they are deviant from the core mechanics of the genre, but they employ quite a bit of the genre staples as well.