That's not me saying it, but some of the folks over there. (See, Nico? That's what happens when you get successful.) Let's be honest here: Final Fortress and Volcano Valley have NOTHING in common, except for the key. And apparently that's enough to be considered a remix. Since there are 24 different keys in music, this means that all songs of the same key are the same song, and therefore there can only be 24 songs in the history of ever. That means Mystic Cave is a remix of the Inspector Gadget theme. That means Robo's theme is a remix of Never Gonna Give You Up. That means Twinkle Park is a remix of Vivaldi's Four Seasons.
You were born with a brain. USE IT.