Continuity mistake: When Toad General calls for the council's attention and announces that Bowser found the Super Star, note his shirt buttons. Then, when he says that the Kongs will never agree because their mad king doesn't make alliances, Toad General's shirt is backwards, his buttons are on the opposite side. (00:24:55 - 00:25:35)
Continuity mistake: During the "Steal the Show" montage, you can see the Earth person in the background. But later, in the elevator scene, it reuses the same person from the previous scene. After, in the dancing scene, the same Earth person behind that water fountain is slow-dancing with the other Earth person.
Continuity mistake: At the start, when Dog takes his food out of the microwave, two game cartridges (Seaquest and Grand Prix) and two controllers for his Atari 2600 are on his table. When he walks back to the couch, those game cartridges have vanished, and there is only one controller on the table. In the next shot, there are two controllers again, as seen in the TV's reflection. (00:02:20)