List of New Super Mario Bros. Wii pre-release and unused content
This is a list of pre-release and unused content for the game New Super Mario Bros. Wii.
During a Q&A session in 2009, Shigeru Miyamoto claimed that he fought with the development team over the tone of the opening sequence, with the team wanting to make it more dramatic. Miyamoto's idea for the opening was to have ships with chains carry a cake on a plate as bait for Princess Peach.
At one stage during development, Shigeru Miyamoto considered making Princess Peach a playable character, like in Super Mario Bros. 2, but eventually decided against it because of how difficult it would be to animate her dress.
The game was originally going to have the Mega Mushroom power up return from the previous game. It would have transformed the player into Mega Mario. However, this caused a problem in multiplayer: because the player who used it would be able to destroy everything while also taking up a big part of the screen, limiting other players, the Mega Mushroom was ultimately removed.
An early picture showed Mario, Luigi and Blue Toad in bubbles. However, instead of Yellow Toad, the picture showed the Red Toad, meaning he may have once been intended to be the fourth playable character. Also, Red Toad is wearing a black vest, while Blue Toad wears a red one.
HUD during gameplay
As seen in 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. Later 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 and brightened up, along with the trademark Mario text. Notably, the life box was sized down, while the score and timer stretched out slightly. Additionally, Blue Toad and Yellow Toad's icons were switched in the final release, with Yellow Toad being third and Blue Toad being fourth.
Also, when a Yoshi is ridden, a music note was originally meant to appear on the upper-right side of the screen. Keys were originally going to appear in the game. When obtained, the key moves to the HUD, next to the lives and coins counters.
In the E3 2009 demo, whenever a character completes a stage, the message "Level Clear!" was seen. Later, "Level" was changed to "Course" in the final build for unknown reasons.
In demos shown at Press Conferences, after finishing each level a results screen would pop up, showing the player how many enemies were stomped and how many coins were collected, which is only seen in the Free-For-All mode in the final game. However, in New Super Mario Bros. U, once the game is beaten, players have access to a purple Records Toad House, containing the aforementioned information.
Flag and midway flag
The Goal Pole and the Checkpoint Flag were originally going to have an image of a skull on them. This was changed to Bowser's emblem in the final version. The skull flag was previously used in New Super Mario Bros.. Additionally, an early image shows the Midway Flag as a circular sign with a skull on it.
"TOO BAD" screen
Originally, this game had a "TOO BAD" screen when the player loses a life, just like 3D Mario games. Later, it was replaced with Bowser's emblem fade.
In the final game, the "Your Turn" message does not appear in single player mode while playing the Power-up Panels minigame.
Early platform models
A later version of the game had the emblem of the player who was controlling the platforms as the end of the trails, while the platform itself was gray with a bolt all the time, just like when they are off in the final version.
Sound effects and music
The underground, desert, castle, and athletic themes and the level clear tunes were ported from New Super Mario Bros., most likely as a placeholder. The snow, forest, lava, and Ghost House songs did not exist.
Yellow Toad's Victory Pose
This was shown in GameStop's E3 demo video. Yellow Toad says "Yay!" and he jumps twice while punching his fists in the air, and it shows that there is no standing animation, so when he stands after his pose, he just freezes for a while.
During the E3 2009 demo, coins had 8-bit sound effects, just as they did in the first New Super Mario Bros.. This was later replaced with different sound effects. The Propeller Mushroom's sound effect was also different in one pre-release build.
Also, the power-up sound effect was originally the sound effect from New Super Mario Bros., but this was changed to the 8-bit version.
New Super Mario Bros. leftovers
This gate allows the player to cross only from one direction. The only re-usable ones are "enter from the right" and "enter from the left"; the variety which allows the players to "enter from below" and "enter from above" can only be used once before permanently locking.
Swinging pendulum platform
A swinging pendulum platform from World 4- was to appear. They self-rotate (the player does not need to attach them to a rotation controller for them to move), and the level editor can adjust their swing arc, speed, and size.
While the game was still in development, Nintendo confirmed that a Red Yoshi was able to be ridden and an artwork was made. However, as seen in a later trailer, Red Yoshi got replaced with Pink Yoshi and the artwork was changed. Blue Yoshi was also set to appear, but was replaced by Light-Blue Yoshi. If a Yoshi was being ridden, then a musical note was going to appear next to the time counter.
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 World 1- in the demo, not in World 6- (as that level was not featured in the demo). In the demo, Morton does not have Skewers stabbing the platforms to the side; instead, there were Lava Bubbles jumping out of the lava. Also, the geography of the arena was different, as it was using the castle tileset, instead of the tower tileset that would later be used in the final build.
In the E3 demo, the players drop from the top of the screen after they enter the boss door, like they did in New Super Mario Bros.. In the final version, the player simply appears on the floor of the boss room.
Blocks and Objects
Early Roulette Block
The Roulette Block was supposed to look like the ones in New Super Mario Bros.. They had different item icons too.
Conveyor Belt Spikes
Spikes were to be on Conveyor Belts, but were taken out for unknown reasons.
Gray ? Blocks
The Bramballs in the E3 trailer had brown feet instead of yellow feet.
Mini Goombas were able to be defeated by running into them. They acted like the ones in New Super Mario Bros., but were changed to the Super Mario Bros. 3 style where the Mini Goombas would stick to Mario and hold him down.
King Bills were able to be defeated, but this was changed in the final version. The animation was later used in New Super Mario Bros. U, where the player can defeat them using the Boost Star in Boost Mode.
While never revealed or used in the game, a power-up that appears to be a "chicken suit" was originally intended to be in the game. Concept art of the suit had been discovered, though its purpose or effects on the characters who were to use it is unknown. The idea was eventually changed into the Penguin Suit. The chicken suit appears in volume 44 in Super Mario-Kun.
The orange Propeller Mushroom was originally a Propeller Suit, with a red letter "P"-like suit with a propeller at its top. It is unknown why it was changed.
Originally, the Fire Toads had mushroom caps which had their respective colors reversed with white spots on them, similar to Super Toad. However, in the final version of the game (and later trailers prior to its release), the Toads' fire forms instead have them with caps with reversed colorations of their respective colors, and with red spots instead of white ones.
Additionally, the early Fire Blue Toad and Fire Yellow Toad had their vests of the same color while their pants remained a maroon like color. However, in the final version of the game, the Toads received a reddish/maroon color for both their vests and pants.
The early power-up icons were very simple. In the final version there was no Mini Mushroom, as it got replaced by a 1-Up.
As seen in this video, Yoshi has a somewhat unfinished animation not seen anywhere else in the game. Since this animation is only viewable by 'hacking' Yoshi into a Castle/Tower Level, it further hints at the theory that Yoshi was originally planned to be able to be used in boss fights.
Additionally, Yoshi does interact with certain enemies differently from Mario, Luigi, Blue Toad, and Yellow Toad, which can only be spotted by hacking the game. For an example, Yoshi cannot safely jump on a Cooligan or a Mechakoopa, but he can eat them. Similarly, Yoshi can defeat a Wiggler by ground pounding it. Another oddity is that Yoshi can defeat a Big Wiggler by eating it, or by spitting a fireball at it.
Information for a Big Buzzy Beetle exists within the game. However, it was not used in any level. The Big Buzzy Beetle can be used as a platform, and will only move continuously in one direction; it does not fall while airborne. It does, however, change direction when it hits walls or collides with certain enemies. Finally, it is immune to every known attack method, apart from throwing a POW block. The enemy concept was revisited and used in later installments.
Unused data for Mini Goombas that act similarly to the ones in New Super Mario Bros. exists in the game. Unlike the Mini Goombas in New Super Mario Bros., they cannot defeat Mini Mario by running into him. 
The only unused track in the game is "cheepfanfare_lr.ry.32".
In the games files, unused voice clips from New Super Mario Bros. and Super Mario 64 DS can be found; these voice clips may have been used for the demo versions of the game.
Items and objects
There were unused platforms. These include four rotating platforms (similar to the ones during the Reznor battle from Super Mario World), see-saw, and controllable platforms like the ones from 1-2 and 7-2 in New Super Mario Bros., respectively. Trampoline platforms that bounce the player to the opposite direction are also seen. These platforms were simply long gray blocks.
Arrows that were used in New Super Mario Bros. were found in the game through hacking methods. They do the exact same thing as they did in said game.
Broken Warp Pipe model
A magenta ! Switch can be found in the game files, but is never used in the game. This ! Switch is an Event Switch. The Event Switch allows an event to activate one of up to four event IDs specified and do something else. It can be used by hacking the game.
An unused key in the shape of a club suit (♧) can be found in the game's files. They may have unlocked doors on Airships.
Larry Koopa model
Snake Block texture
Toad balloons were originally meant to be Green Coins. This can be proved because the name of the object is "EN_GREENCOIN". "obj_coin.arc" also contains a model and texture for a Green Coin, but is never used in the game. The object was later used in New Super Mario Bros. U.
An object that slightly resembles a Magic Ball appears in the game's data.
In the World Map folder on the disc, left behind is an unused configuration file for the "Collected Star Coins" screen ("CollectionCoinCourseSort.arc"). From it, early level layout can be assumed.
Concept box art
A proposed box art for the game featured a hand-drawn sketch depicting Mario, Luigi, and the Toads facing Bowser and the Koopalings. This concept box art was included as part of a recruitment kit for prospective Nintendo employees.