Love 'Em and Leave 'Em - S1-E8
Continuity mistake: Throughout the episode, the number of fingers Queen Rotunda has on each hand switches between four and five several times.
Love 'Em and Leave 'Em - S1-E8
Continuity mistake: When Mario runs over to help Queen Rotunda, he has his cap on, but in the next shot, it disappears. (00:09:29)
Love 'Em and Leave 'Em - S1-E8
Revealing mistake: When Mario and his friends are running through the maze, his friends are briefly layered over some bushes. (00:06:34)
The Great Gladiator Gig - S1-E6
Continuity mistake: When King Koopa falls into the arena, the rings around his shell's spikes are colored orange, like the spikes, instead of green. (00:15:49)
The Great Gladiator Gig - S1-E6
Continuity mistake: When Tryclydius says that he does not know why King Koopa has to tell him three times for him to understand, his red eyelids turn white like his eyes. (00:04:57)
The Great Gladiator Gig - S1-E6
Continuity mistake: When Toad reconsiders being called a creature, his red vest turns white, like his cap. (00:06:48)
Continuity mistake: After Mario and Luigi pick up their weapons, they can still be seen on the ground. (00:11:39)
Mario meets Koop-Zilla - S1-E28
Revealing mistake: In the live action segment, when Madam AGoGo begins reading the Bros' fortune, a lightbulb can be seen making the crystal ball glow. (00:17:25)
Revealing mistake: When Mario and his friends laugh at the end of the episode, Mario appears to be standing in midair. (00:16:54)
Continuity mistake: When Mario says that Karate Koopa is finished, he is not holding anything, but in the next shot, he has his staff. (00:15:41)
Revealing mistake: When Karate Koopa catches Princess Toadstool and Toad trying to escape, his legs and part of Princess Toadstool's dress are cut off for a few frames. (00:13:49)
Revealing mistake: When Mario and his friends kick the Ninjis when being surrounded by them, one freezes in midair while another duplicates itself. (00:12:48)
Continuity mistake: When Luigi swings his nunchucks a second time, his sideburns disappear. (00:12:40)
Revealing mistake: When Misaki says he cannot break the chains, his air bubbles occasionally freeze. (00:09:45)
Other mistake: When Luigi takes the washer from Misaki, his hand is behind it, but he is still able to get it. (00:07:49)
Continuity mistake: When Misaki says that fear never enters the vocabulary of someone training to be a martial arts expert, Mario and Luigi's gloves disappear. This also happens when Misaki says he will award them black belts. (00:06:24 - 00:16:23)
Mario meets Koop-Zilla - S1-E28
Continuity mistake: When Mario walks over to Koop-zilla after he throws him a second time, buttons appear on the back of his overalls. (00:13:07)
Mario meets Koop-Zilla - S1-E28
Other mistake: When Luigi asks how he and Mario are going to escape Koop-zilla, the strap on his goggles is missing, and shortly after, they completely disappear. (00:10:02)
Mario meets Koop-Zilla - S1-E28
Continuity mistake: When Koop-zilla says that destroys a city, it makes him hungry. One of the orange spikes on his shell turns green. (00:07:48)
Mario meets Koop-Zilla - S1-E28
Audio problem: When Luigi asks how King Koopa became so large, he briefly speaks with King Koopa's voice. (00:04:35)