The course Dry Dry Ruins that is based upon Egypt has cacti that serve as obstacles where the player will spin out upon colliding into. Egypt, that the course's theming is based after is in the Sahara desert in North Africa that does not have cacti, but instead cacti are in South Africa and some other parts of the world like the Middle East, Southwestern America, and Northern Mexico.
Princess Peach's hair is supposed to be tied in a ponytail as intended. In the game's opening cutscene and on the victory screens after the ending credits, she has her hair down.
In the game's promotional artwork of Bowser driving his Flame Flyer with a Spiny Shell handy, he is holding the item in his left hand. In the game, characters (and Miis) use their right hands when throwing items.
Waluigi is in the large weight class, which doesn't make sense because he's a twig.