Geno Penguin

Aside from an unfinished model, the files for night Toy Field contains all the textures from the final version's Toy Field. This suggests that the developers were going to use the final stadium as a basis for creating the night stadium, but never got past designing it. (2 / 2)

In Mario Super Sluggers, an unfinished night version of Toy Field is present in the files for Toy Field. It's filename (sta00b) suggests that it would've been selectable on the main menu when switching from day to night (Night stadiums have their filenames end in "b"). (1 / 2)

It appears that this was not the intended texture, as an unused reflection texture can be found in the files for the egg. Below is a mock-up of the Yoshi Egg with the unused intended reflection texture, instead of the egg texture as it's reflection: (2 / 2)

In Mario Super Sluggers, the Yoshi Egg in Yoshi's Egg Swing uses the egg texture as a reflection. This results in the egg looking oddly glossy on the green spots. (1 / 2)

This error does not exist in Daisy's low-poly model. Viewing the UV map shows the points are no longer connected to each other across the collar texture. (2 / 2)

In Mario Super Sluggers, Daisy has a UV mapping error in the back of her hair. The error is caused by one point of the UV map connecting across the collar area, leaving the transparent area to show on the back of Daisy's hair. (1 / 2)

In Mario Super Sluggers, the giant statue of Bowser Jr. in Bowser Jr. Playroom has an section for a stomach in it's texture. However, the statue doesn't have the stomach mapped anywhere, leaving it blank in-game.

@MarioBrothBlog The developers for Mario Kart Arcade GP seem to have broken that rule, as an unused graphic for an early version of the character select screen exists with edits of a few pre-existing renders for the playable characters.

An official 2005 guide for the presentation of Mario character illustrations, used internally at Nintendo of America, prohibits the modification of official artwork. Here are the examples of prohibited illustrations it lists.

@alaxsandwich The first thing I thought of was the Barrel Batter minigame from Mario Superstar Baseball.

Man i wish there was a place to hone my skills at baseball The ever reliable mini-games within Mario Super Sluggers:

@moipcss Nice discovery! Wonder if this was some leftover they used from the modeling program used to animate the characters, hence the filename for the "ponytail" bones.

In Mario Superstar Baseball, Birdo's model oddly has two cuboids inside of her bow, which act as bones for the bow when animated in-game. These two bones are internally named "Bip01 Îßưð٠1" for the green one, and "Bip01 Îßưð٠2" for the blue one.

@B_squo Hammer Bro's icon was reused in Yoshi Touch & Go for the ranking icons, and Shy Guy's icon was reused in Mario Kart DS, where it goes unused in that game.

If you're familiar with unused Mario Kart Wii content, you might remember these 2 unused icons of Hammer Bro. and Petey Piranha respectively. It turns out, these icons don't originate from MKWii. In reality, they previously appeared in an early build of Mario Superstar Baseball!

In Mario Super Sluggers, the Mini Boo is an item that makes the ball explode into Boos, rendering it invisible. The item's default model in the files stores all the Boos clumped together, making them appear to be some kind of deformed amalgamation.

(Forgot to include this info graphic)

The info graphics when starting the mode for the first time exist fully translated, albeit unused. Compared to National Battle in the Japanese version, this mode would've had the player battle online ghosts from around the world.

In Mario Kart Arcade GP DX, the US version has unused menu graphics for a mode known as "Worldwide Versus." This mode became known as "National Battle" in the Japanese version, suggesting that US cabinets were planned to have a similar mode, but scrapped during development.

The ranks the player can achieve were also translated, but left unused in the files. The bronze ranks are known as "Racer Levels", while the higher ranks are "Ace Levels."