Final Fantasy is very much a theme park for the series. It regularly references other games or weaves their themes into the very fabric of Eorzea and beyond. Occasionally, it straight-up implants entire characters or plots.
Despite all that, it's done surprisingly very little with the series' golden goose: Final Fantasy 7. Sure, there's the Gold Saucer. And materia melding. And Cloud's Advent Children fit. And the Fenrir motorcycle. But as for actual characters or dipping into the game's world? There's not all that much to be found.
