Continuity mistake: At the beginning of the episode, the circus for Dome City can be seen, even though Mario and his friends have not hosted it yet. (00:01:30)
Continuity mistake: The score for the tennis match can be 30-love before Luigi announces it. (00:01:35)
Continuity mistake: When Luigi explains that ball boys pick up balls instead of eating them, the number of fingers he has on each hand changes from five to four. This also happens when Mario says they should check out the circus, along with Mario. (00:02:02 - 00:04:22)
Continuity mistake: When Kootie Pie is putting up a poster, her cream snout turns orange like her body. (00:02:09)
Continuity mistake: When King Koopa is first seen in a Koopa Clown Car, the rim around it is white, but in the next shot, it is green. (00:02:45)
Continuity mistake: When King Koopa says, "The cave people will become food for his dinosaurs," his cream claws turn yellow like the spikes on his shackles. (00:03:03)
Revealing mistake: When two cave kids enter the Warp Pipe, they move without moving their legs. (00:03:04)
Continuity mistake: When Mario goes out of bounds to hit the ball, he is briefly layered behind Yoshi. In the same shot, the white stripes on his gloves turn blue like his shirt. (00:03:16)
Revealing mistake: When Mario and his friends reach Kastle Koopa, a railing is layered over Mario. (00:04:07)
Audio problem: When Yoshi asks what doom is, his mouth moves before any sound comes out. (00:04:13)
Revealing mistake: When Yoshi says the circus is more fun than tennis, a line on his underbelly is layered on his left arm. (00:04:17)
Audio problem: When Big Mouth is hit by a pie, the audio is unsynchronised. In the same shot, Big Mouth's body is missing. (00:05:28)
Revealing mistake: When the pie launcher starts launching pies, the crank is not moving, even though King Koopa is cranking it. (00:06:11)
Revealing mistake: When a Rex trips on a pie, the nose on its costume overlaps on Big Mouth as he passes. (00:06:31)
Revealing mistake: When Mario and Luigi realise that the clowns are dinosaurs, part of Mario's mouth briefly detaches from his face. (00:06:35)
Continuity mistake: When Mario falls into the cage, King Koopa disappears. (00:07:29)
Revealing mistake: When Mario suggests grace to the Dino-Torch, his moustache overlaps on it. (00:08:18)
Continuity mistake: When Princess Toadstool throws the Fire Flower to Mario, the underground is depicted at ground level. (00:08:34)
Revealing mistake: When Koopa football players start throwing baseballs at Mario, a block is layered over one of them. (00:08:57)
Revealing mistake: After Mario jumps over the statue, he is layered in front of and behind the wall. (00:09:14)
