Continuity mistake: When the Mario Bros. speed up their car to get to the rebel fort, in one shot both of Mario's hands are on the steering wheel, and in the next shot his right hand is on some sort of lever that makes the car go faster. Luigi's hands also change position in these shots.
Continuity mistake: When Mario, Luigi and Toad say goodbye to the Princess, Toad is standing at the front of their car, Luigi in the middle, and Mario at the back. Two shots later, the order changes to Mario at the front, then Toad, and Luigi at the back of the car.
Continuity mistake: During the fight sequence, Koopa ties a rope around the Plumbinator's metal body and pulls the Plumbinator over to him. Luigi cuts the rope with a pair of scissors, causing Koopa to fall back. The part of the rope tied on the Plumbinator disappears for the rest of the scene.
Continuity mistake: At the start of the fight between Robo Koopa and the Plumbinator, Koopa fires a black bomb. The number of bombs in this sequence keeps changing, from 1 when he fires it, then 3, then 2 when the Plumbinator sends the bombs back to Koopa, then 3 again, and finally 2 when Koopa dodges the returned bombs. Also, the color of the bombs keep changing from black to red.
Continuity mistake: After Luigi says "Let's play cupid," he peeks around the corner along with Peach and Toad down at Mario going down the aisle with his "bride-to-be." Luigi, as expected, has been wearing green all episode, but when you see them peeking around the corner, Luigi's hat has become red. In the very next shot showing Luigi from behind, his hat has returned to green.
Continuity mistake: When Mario, Luigi, Bunsun and Dr. Nerdnik are about to be crushed by the electric pole, when Luigi moans "we're doomed," he is in front of Mario. In the next shot, Mario is looking ahead while saying "doomed, schmoomed." In this same shot, Mario pulls Luigi over to a nearby fire hydrant, and Luigi moves onscreen from Mario's right. Therefore, Luigi has changed position.