List of New Super Mario Bros. Wii pre-release and unused content

Beta Elements from the game New Super Mario Bros. Wii.

Propeller Mushroom
The orange Propeller Mushroom was originally a Propeller Suit, a red letter "P"-like suit with a propeller at its top. It's unknown why the creators changed it into a Mushroom.

Level Designs
Many of the platforms were redesigned as many of them were orginally plain in color. There are also differences in mechanics of some of the platforms. There was earlier going to be platforms moving on their own, close by growing and shrinking pipes, but those platforms can now be controlled by players doing something specific.

Fire Toads
Originally the fire Toads had caps which had their respective colors reversed with white spots on them. In the latest screens from the games, the Toads instead have red spots on their caps.

HUD during gameplay
During the early screenshots of the game, the HUD originally appeared transparent during gameplay; additionally, the text appeared very different, with only generic font; possibly as a placeholder. Recent screenshots and videos of the final build show that the HUD is now solid (only turning transparent if a player goes behind it), certain icons were updated or brightened up, and along with the trademark Mario text. Notably, the life box was sized down, while the score and timer stretched out slightly.

Also, when a Yoshi is ridden, a Music Note appears on the upper-right side of the screen. This may have been deleted because that people may have been under the impression that the note stands there for no reason.

Red Yoshi
While the game was still in development, Nintendo confirmed that a Red Yoshi is ridable (even an artwork of it has been made, saying that it would stay so). However, after a newer trailer, Red Yoshis haven't been seen again in this game, but instead, Pink Yoshis have been added (the artwork for the Red Yoshi has changed to match the current change). It may be possible that the Pink Yoshi replaced the Red one.

Blue Yoshi
The Blue Yoshi was also supposed to be in New Super Mario Bros. Wii ever since the gameplay, a Blue Yoshi is rideable and was confirmed, but it is possible that Light Blue Yoshi replaced Blue Yoshi in the latter.

"Level Clear!"
In the E3 2009 demo, whenever a character completes a stage, the message "Level Clear!" appears. It has since changed to "Course Clear!" for unknown reasons.

Sound Effects
During the E3 2009 demo, the coins had 8-bit sound effects, just as they did in the first New Super Mario Bros., but that was later replaced with most recent coin sound effects, the exact same ones from Super Mario Galaxy.

Dropping in on the Koopalings
In the E3 2009 demo, after players go through the boss door, they all fall from the top of the screen and into the boss room, as the initial Larry and Morton videos showed. This was just like in the original New Super Mario Bros., where the player also enters the Bowser Jr. battles the same way. In the final version, the players are already on the ground when the boss room loads up.

Boss changes
In the first battle against Larry Koopa as presented in the E3 2009 demo, whenever he goes into his shell, he barely covers any ground. Also, the first battle with Morton was held in the World 1 Castle in the demo, not the World 6 Tower (as that level wasn't featured in the demo). Morton also doesn't have spiked pillars stabbing the platforms to the side; instead, there are Podoboos jumping out of the lava.

Flag and Midway flag
The flag and the midway checkpoint were originally going to have an image of a skull on it, but it changed to Bowser's face in the final version.

Power Up Panels
In the final game, the "Your Turn" message does not appear in single player mode.

Penguin Suit
The Penguin Suit was going to have white eyes with a blue pupil but changed with Black Eyes

Enemies
Kab-ombs, Mr. Blizzards, Stretches and Bowser Statues were meant to appear but they were cut out as soon as the game was released.