* FanNickname: Werehog for Sonic's lycanthrope form, until Sega [[SureWhyNot adopted it as the official term.]] People also call Orbot (Eggman's assistant mini-robot) "Ergo," because [[VerbalTic it keeps using that word]].
* GenreKiller: This game's reception was pretty much the final nail in the coffin for fully 3D ''Sonic'' games. Starting with ''VideoGame/SonicColors'', the series would instead adopt a style more like this game's daytime half.
* RecycledScript: While not identical, the plot of ''Sonic Unleashed'' is very similar to that of ''[[VideoGame/SonicAdvanceTrilogy Sonic Advance 3]]'', which was released four years earlier.