On the GameCube? Skies of Arcadia was a Dreamcast game.
He must mean Skies of Arcadia Legends, an enhanced port of the game for Gamecube.
I had no idea there was a port of this game to the GameCube. I'm skeptical about the "enhanced" part though, as Skies of Arcadia looked superb on the progressive-scan Dreamcast. I cannot imagine that dropping down to 480i on the GameCube did anything good to the game's graphics quality.
The enhanced part is that it's a director's cut with more content and it has a more stable framerate.