Continuity mistake: Sarah sits in her fake room, picks up the book, 'The Labyrinth' and is seen in her reflection. She then says, "Through dangers...take back the child you have stolen." When the Junk Lady asks, "Don't you like your toys?" and also when she gives Sarah the music box, Sarah is seen. In each shot the things behind Sarah's shoulders and in front of her are different, yet, the Junk Lady did not add anything between these shots.
Picture submitted by Super Grover
Continuity mistake: After Gerry gets smacked in the face by the 'broken' suspender clasp, we see the silver clasp land under the dresser. Yet, when he's moaning and lifting his leg to get onto the bed, we can actually see the clasp still intact on the front suspender that came loose, which is dangling right behind him (just look between his legs). Of course, in the next shot, that clasp is gone. Since the silver clasp is one of the plot points, this is bizarre to say the least.
Continuity mistake: When John and Catherine are in the hangar at the runway, the Cessna's tail number is N3035C. When the plane is shown in the air, the number is N3973F. When they land, the tail number has changed back to N3035C.
Continuity mistake: In the bedroom scene the girl is holding a clear cup full of beer. The camera goes off her and when it comes back she is holding a blue cup. The camera goes back off her then on her and the cup is clear again.
Continuity mistake: When Sam is in his bedroom, after he finds the Cube sliver it falls and dramatically burns a hole through the floor into the kitchen. But Sam's bedroom is over the living room (there is nothing on the ground floor below Sam's elevated bathroom, and in the first movie Jazz hides in this open space), and the kitchen is actually located between the den and dining room, at the other end of the house. If they were to follow the actual floor plan of the house, the Cube sliver would have landed in the area of the piano in the living room, but where would the fun have been in that?
Audio problem: When Oh and Tip are searching through the crashed Gorg drone, Pig's meow is briefly heard, but he is not with them.
Continuity mistake: As Cinderella and the prince are leaving the home, her stepmother is standing on the staircase watching them. In the close-up there is a sconce with three candles on the wall to the stepmother's right. In the long shot the sconce and candles have vanished.
Plot hole: Even if boys of that age had the technical know-how to quickly repair Jeeps over 20 years old (seriously?), any gasoline in the tank would have long become unusable, the tires and lines would have rotted away, and the electrics would all be dead. Now if it was in the desert or a dry garage, it may have survived, but it's on a tropical island, in a shed that has all sorts of holes in the roof, leaving it exposed to every kind of weather the island could throw at it.
Continuity mistake: When SpongeBob and his crew are stranded on pelican island, Squidward releases a puddle of ink on the ground because he is nervous. When SpongeBob dabs the pen in the ink, in the next shot the ink is completely gone.