Seems all too easy... how about the CD-i Zelda's? Or Metal Slug Defense? Be it as it may, it all comes down to this: There's always room to discuss to what degree a game (book, film, comic etc.) belongs to a series canon and to what degree it doesn't. You seem to be a fan of easy answers, though, so carry on and don't bother to question pre-chewed definitions, nothing wrong with that. Nothing at all.?! Yes, very much so. Simon's Quest, Double Dragon neo geo, Adventures of Link, SamSho RPG are just a few examples off the top of my head of sequels in which the gameplay was radically changed, yet are still clearly part of the game series.