Revealing mistake: When Princess Toadstool spots King Koopa, King Koopa and his minions are layered over a wall. (00:07:14)
Continuity mistake: When King Koopa first appears, he has two Koopa Troopas with yellow underbellies. But when Princess Toadstool says that he tricked the Mario Bros, one of the Koopa Troopa's underbellies turns purple. (00:09:34)
Continuity mistake: After Princess Toadstool says that King Koopa tricked the Mario Bros, King Koopa's yellow eyes turn white. This also happens after Toad says that the Mario Bros. are safe. (00:09:39 - 00:10:18)
Continuity mistake: When the Mario Bros. pass King Koopa's minions after surviving the first trap, the lenses on Mouser's glasses disappear. (00:11:49)
