Continuity mistake: When he sees Meg in the river of death, he reaches down and touches it. Then, when he jumps in, he makes a dive of at least 50 feet. (01:11:25)
Continuity mistake: When Meg and Hercules are walking down the stairs in the garden, Meg has a sheer purple shawl, but when Pain and Panic (disguised as birds) tell her to stop fooling around, it disappears. Then, a few shots later, when she tells Hercules not to thank her just yet, it has reappeared. (00:57:00 - 00:58:00)
Continuity mistake: During Hades' meeting with the Fates, he walks to a table to explain his plan. Between shots the things on the table change.
Continuity mistake: In the shot of the gods after Hades makes his joke about moussaka, Dionyssus is close to Aphrodite and Athena's owl is on her left hand. Then as Hades asks "Is this an audience or a mosaic?", Aphrodite is further from Dionyssus, and Athena's owl is on her right hand.
Continuity mistake: When Hercules opens the case, all that falls out are two pots, two bowling pins, a helmet, a sword, and two pairs of armor. A purple cape, two shields, many other pots, a sandal, a trophy, and a white ball with a blue stripe are among many of the additional items that appear out of thin air in the very next shot.
Continuity mistake: As the Fates cut their first victim's string of life, between shots they move further away from the nearby window.
Continuity mistake: When Hades says "Here I am kind of river guardian-less" you can see a chess piece of a centaur on the board near to a lot of other pieces. The when Meg flicks the centaur off the board, the other pieces are gone.
Continuity mistake: In Thebes, when a vendor opens his cloak and asks if he wants on sundial, his fingers go from being underneath the cloak to over it.
Continuity mistake: In the first scene involving the Fates, the hands of the green one are perfectly fine, and it is not until Hades places the eyeball in her hand that all the disgusting brown spots and hairs appear.
Continuity mistake: When Hades forms a chessboard to show Meg his plan, the chess-pieces on it change between shots.