Continuity mistake: When Hades forms a chessboard to show Meg his plan, the chess-pieces on it change between shots.
Continuity mistake: While watching today, I realized right before "Go The Distance' when Hercules' mother is putting the wrap on him, originally it's green, but throughout the song, it's blue. Part of me thinks that it's supposed to be the shadows from the sunset, but looking again, it seems that it suddenly changes from green to blue. Especially since during the lightning storm in the song the color doesn't change much at all.
Continuity mistake: When the pillars are about to crash on the pot-maker, he has eight pots and his hand. Then after they don't, and he breathes in relief, there are only six pots in his hands.