Continuity mistake: Rumplestiltskin looks completely different in this movie than he did in the previous film Shrek The Third; Prince Charming momentarily talks to Rumplestiltskin in the tavern during the third film, and the character looks completely different, has a different voice and different demeanor.
Continuity mistake: In the scene where Shrek goes back to the swamp after signing the contract, he realizes that Fiona isn't there and pulls out the contract to read it. He then notices something flying overhead and looks up to see the witches. In the next shot, we see no contract in Shrek's open hands.
Question: What happened then to Prince Charming or Fairy Godmother? In Shrek 2, they did mention that it was the Fairy Godmother who cursed Fiona. So how come Prince Charming never rescued her instead of Shrek (since he was never born in Rumpelstiltskin's timeline)? The King and Queen may have disappeared but at least Prince Charming could have still saved her.
Question: In the beginning, the king and queen are shown riding in a carriage. However, before watching this movie, I viewed Shrek 3 where the king had turned into a frog and died. If he died in 3, how did he come back to life in this movie? This was before the king and queen signed any contract and vanished, so magic was not involved in his being alive.