Revealing mistake: When Alex says they should go find the penguins, he says "To home" and Marty, Melman, Gloria and Julien place their hands on top of his hand. In the next shot it shows all of them together. But due to the position of Julien and his arm length, it would have been impossible for Julien to have his hand fully placed on Alex's hand. (00:05:05)
Revealing mistake: When Ralph returns to the penthouse after destroying Vanellope's kart, he goes out onto the balcony and we can see the corner of the 'OUT OF ORDER' sign reflected on the window to Ralph's left. The piece of tape is missing in the reflection.
Revealing mistake: In the opening shot, when it pans towards Mr. Leonard and the old lady, the street lamp that is positioned to the right of Mr. Leonard's car begins to pass in front of the car even though it is placed on the other side of it. (00:00:20)
Revealing mistake: When Scrat removes the giant acorn in Scratlantis the city is immediately flooded. Everyone in the background is blown away by the sudden rush of water. However, both Scrat in the background and Scrat's host (slightly off-camera) in the foreground don't move and don't seem to be affected by extremely strong flow. (01:18:50)
Revealing mistake: When Sparky's tail pops off there is a hole where it popped off. But when the tail goes into the bucket the hole is gone.
Revealing mistake: During Jack's memories, when he is holding the antlers up to his head, Jack's sister's boot can be seen coming through the fabric of her dress.