When you arrive at Bowser's Keep via the Cloud Bus, a group of people can be seen on Vista Hill, celebrating your getting into the keep. But if you visit Vista Hill on the map again, they are gone.
When the enemy called "Formless" is hit by a special technique and becomes a visible enemy, the dialogue box calls him "Mokuka." But the enemy information box in the fight calls him "Mokura."
When the enemy called "Heavy Troopa" is preparing to do his big attack, the text at the top of the screen reads "Heavy Troopa's ready to launch." Later, a pallet-swapped version called Tub-O-Troopa appears, yet this same message is used, erroneously calling the enemy Heavy Troopa.
The desert section of Land's End depicts whirlpools as a means of progressing further - only if Shogun is in it and once he's defeated in battle. Whirlpools are only possible in water, so quicksand would have been the answer instead.
The Japanese title screen depicts the copyright year as 1995, even through it was released in March of 1996. This is corrected in the North American version that was released two months later.
In the original SNES version, when Peach loses her crown and other accessories during an arranged marriage to Booster after being slammed into the altar, they are still shown on her body while the crown of a larger size is on Booster's head. This is fixed in the Nintendo Switch remake where she is properly shown sans the crown and accessories she is supposed to have lost during this event.
The manual for the North American version does not list Princess Toadstool's character profile and stats, despite the fact that she joins the party later in the game after defeating Bundt. So technically, the instruction manual is considered unfinished.
You fight Yaridovich, on the main map screen, on what appears to be a small coastal beach area at midday. But the actual fight takes place on a cliffside, at sunset.
The item called a "Troopa Shell" is actually from a Koopa PARAtroopa.