Wild Mass Guessing pages are Spoilers Off. You Have Been Warned.
Refrain from using first-person pronouns, please. This is a WMG page, not a forum.
- One of the level names shown in the trailer was "Welcome to the Flower Kingdom." Guess what the only prior reference to the "Flower Kingdom" in any Mario media was?
- The caterpillar hanging onto Luigi in the box art may be his expy. The crown on his head may be a clue that not only is he royalty but may have also been transformed.
- If he does appear, his name will probably be localized to "Prince Spring" or "Prince Sunny" since "Haru" is the Japanese word for "spring", and the name can mean "sun".
- While his expy-ness may still be evident, Prince Florian is shown in his caterpillar form before Bowser shows up, so that seems to be his normal form.
- Considering that the trailer showed more than just 4 playable characters, it's possible that there will be even more, even from spin-offs. Possible choices include:
- Wario
- Waluigi
- Rosalina
- Toadette
- Confirmed
- Geno
- Red Toad
- Regular Toad
- Bowser (if the below theory of him not actually being the villain is true)
- Pauline
- Birdo
- Donkey Kong
- Paper Mario
- This might happen, as badges are a new feature and the only games with them have been Mario RPG and the Paper Mario games.
- Foreman Spike (there were leaks a while back saying he would be in the next 2D Mario game)
- Bowser Jr
- Only if the theory of Bowser not being the villain is true. Otherwise, him fighting his father will not make sense.
- He fought his own father in Bowser's Fury.
- Only because Bowser wasn't himself.
- Likely jossed. The August Direct shows him assisting Bowser.
- The Babies (Baby Mario, Baby Luigi, Baby Peach)
- Kirby and friends
- That one's kinda pushing it. This is a Mario game. If it is true, just Kirby. No one else.
- Crossover characters in general are unlikely. But like the above comment says, if this ends up being true it'll just be Kirby.
- Toadsworth
- One of the Koopalings (if the theory below is true or if the Koopalings make an appearance in the game)
- Metal Mario (And he’ll be given a unique moveset).
- Technically confirmed. Characters' metal forms appear as a Wonder Effect in a level near the end of the game.
- E. Gadd
- Robo Mario
- The penguin king.
- Stanley the Bugman
- Confirmed. Nabbit and Toadette are also playable.
- Adding onto this, Bowser is a playable character who will be unlocked when it's revealed he's not the Big Bad.
- For the record, Bowser Jr. is shown to have transformed in the trailer. It's impossible to tell if he's brainwashed or not, but this could give valid reason for Bowser to be on Mario's side - Bowser's Fury but with the roles reversed.
- Well, for what it's worth, the trailer shows that the flagpoles still have the Bowser emblem on them.
- To be fair, it's a staple for Bowser's emblem to be there, and it would be weird if it were anyone else. Plus, it may be the game's way of hiding the true Big Bad.
- Likely because of a few things. Either it might spoil that there's a new villain taking Bowser's spot, could be a case of Grandfather Clause, or perhaps Bowser's after something else. Considering Peach is playable, the latter may be the case, like with another game in which Peach is among the main group.
- Bowser has probably still caused the immediate problems, hence why we're still fighting Goombas, Troopas, and Hammer Bros., but under someone else's direction. It wouldn't be the first time.
- The ESRB rating mentions the villain to be Bowser, possibly decreasing the chances of this being true. But it isn't Jossed quite yet, as it's still possible that they are simply hiding the true villain.
- Seemingly jossed. The second trailer shows that the plot revolves around Bowser using a Wonder Flower to fuse with Prince Florian's castle into a sentient airship and wreak havoc across the Flower Kingdom. Of course, there could be some sort of plot twist explaining that he was actually manipulated or baited by someone into doing it, since there is something purple around his airship in the first trailer.
- Fully tossed. Bowser is the definite villain. The purple smoke is merely coming from the amount of wonder energy used and corrupted by Bowser.
- White Rabbit boss
- Possibly returning white rabbits?
- Dodo or bird boss
- Such as Wingo
- Caterpillar boss who is a Wiggler
- If the theory below about the caterpillar with the crown being Evil All Along is true, he will represent this character to some degree.
- Cheshire Cat boss
- With King Totomesu in the role.
- Duchess boss
- Birdo
- The Dormouse, Mad Hatter, The March Hare working together as one boss
- What if the Dormouse is or is based off Mouser? Maybe Topper could be a Composite Character of The March Hare and The Mad Hatter.
- Connecting to the theory above, The King of Hearts boss who will turn out to be Bowser under mind control again.
- The Queen of Hearts will be the final boss and the one controlling the enemies and bosses.
- And she will be represented by The Golden Diva.
- Jossed. All of the bosses are Bowser Junior, and Bowser is the final boss. No Alice in Wonderland references to be found.
- And she will be represented by The Golden Diva.
- It is likely possible that they have not been implemented yet in the build used for the trailer. The trailer for New Super Luigi U showed Luigi using Mario's physics. Plus, Yoshi can still flutter jump and allow the other players to ride on top of him.
- Semi-confirmed. While Yoshi and Nabbit have unique properties, everyone else plays identically.
- Jossed. Though that would've been cool...
- That could make sense if it had been a Wonder Effect, limited to part of a specific course. But since the addition of the item storage, power-ups can almost always be used in any course in the 2D games. Would they design every course in the game to work with a power-up that doesn't let you jump? Is that even a fun idea for a power-up in a platformer?
- If you notice, Elephant Mario just walked up the slope, when a normal player would just jump it. This is likely the case.
- Jossed. The Mario Wonder Direct shows Mario jumping while in Elephant form.
- Jossed for the most part. The Alice in Wonderland nods don't go beyond what was mentioned.
- Likely, given we do see a fountain nearby with some elephant symbols.
- Confirmed. when a character turned into an elephant goes underwater, he/she will store it in their trunk and can shoot it forward.
- That or he's an antagonist.
- Jossed. He's not in the game at all.
- Or his voice simply changed, nothing more, nothing less, receiving a different direction to match with the wackier direction used in Wonder. We've been so used to hearing mostly the same recycled Mario lines across decades' worth of games, him going through a Vocal Evolution is such a foreign concept. Not that it never happened before: even though Charles Martinet was still voicing them, both Mario and Luigi's voices have changed in recent years, something that started around the time Super Mario Odyssey was released, but the difference became more noticeable with Luigi's Mansion 3 and Mario Kart Tour, as not only their voices have become noticeably deeper and sounded a bit aged, but with Luigi's Mansion 3, Luigi's voice became raspier and more nasal than before, resulting in a lot of people not immediately recognizing it as Charles' because of it.
- He voiced a character in The Super Mario Bros. Movie who uses the classic Mario voice and sounds perfect, so that likely isn't the reason. Then again, the movie was planned for at least a decade, so who knows how old those clips are.
- Wouldn't Nintendo have said something if they were to suddenly recast Martinet? They did immediately confirm Mario would be played by someone else with the movie that was released back in April. Recasting the guy that has been voicing Mario for 30 years in the series so suddenly just doesn't feel right.
- And even if they didn't, Charles himself surely would've said something.
- With the news that Charles Martinet is stepping down from playing Mario, this could be possible. However, it's currently unconfirmed if Martinet is playing Mario and Luigi in this game as a last hurrah or if this will be the first game with a replacement voice actor.
- Sadly, it's confirmed that Martinet is not in Wonder.
- Jossed. The Broodals are not in this game.
- While he is definitely not human as originally thought, Florian being a mainstay is still a possibility.
- The only confirmed case of this is the Wiggler who the player races with for a Wonder Seed. This could possibly also apply to the dancing Ninjis, though it's hard to tell.
- Jossed, he serves as a way to give you extra abilities with badges.
- Not explicitly confirmed, but the Mario Wonder Direct confirms that both Captain Toad and Toadette will appear, so possible. Toadette in particular is confirmed to be playable.
- Jossed. Captain Toad is not playable, merely being an NPC the player can find on the world map. Toadette is playable alongside Mario's group, and Toadsworth is not in the game at all as is standard for modern Mario.
- More likely the former since the mainline games tend to ignore the RPGs.
- Unlikely, as the game's eShop page mentions Yoshi as a distinct playable character, and no other Wonder Effect (namely, the spike ball transformation) has been shown to change the UI's character icons.
- Also, the very first scene with a Yoshi, the green one, has him tagging along with Mario. And Said Yoshi also appears in the key artwork of the game, alongside all the other playable characters.
- Also also, unlike every known transformation, the Yoshis have no Morphic Resonance with the other characters beyond the vaguest overlap in color.
- Jossed. The four Yoshis are separate selectable characters.
- Jossed. It's not a dream.
- Seemingly jossed, although there's a possibility that Bowser was manipulated or brainwashed into using the power of the Wonder Flower to merge with King Florian's castle by someone. It is unlikely he knew what that Wonder Flower would do on his own, or even knowing Wonder Flowers exist and they have mystic properties.
- Jossed. No Wart in sight.
- Either that, or it's another wonder flower effect.
- Confirmed to be a Wonder Flower effect in the Mario Wonder Direct.
- Wario (And his boss theme would be a remix of 'Hurry Up!')
- Waluigi
- King Bob-Omb
- King Boo
- He appears in one of the trailers, but it's unknown if he's a boss or just a level gimmick.
- Jossed. He's a Wonder Effect.
- Petey Piranha
- Fawful
- Assuming they would be willing to take characters from spin-offs.
- Metal Mario
- He has been treated as its own entity in spin-off games, so he can count.
- Jossed. Metal forms of characters appear as a Wonder Effect.
- Foreman Spike, mentioned above.
- Gooper Blooper
- Raphael the Raven
- Goomboss
- The Golden Diva
- Donkey Kong (In a friendly rival-type fight).
- King K. Rool.
- Dark Bowser
- A boss similar to both him and Bowser Jr. appeared in the trailer, so why not the man himself?
- Bowser's brother
- Wart, if the theory of him being in the game is true.
- Prince Haru
- King Whomp
- The Shake King
- Pink Gold Peach
- The Koopa General
- Birdo
- Blue Toad (Wanting revenge for being demoted to a secret character in New Super Mario Bros U Deluxe).
- Jossed, the second trailer shows that he's a (Non-secret) playable character in Wonder.
- The caterpillar (If the below theory about him being Evil All Along is true).
- Rudy the Clown/A Hidden Figure.
- Wingo
- Mouser
- Cloud N' Candy (She'll also either be unexpectedly hard to defeat or a self-aware Zero-Effort Boss)
- Count Cannoli (Or maybe the actor playing him)
- Tryclyde, Fryguy, Clawgrip, or Robirdo
- Tatanga
- King Ka-Thunk
- One of the Broodals, or maybe all of them in a Wolfpack Boss fight
- Cosmic Mario
- Jossed, but an evil version of Mario called Dark Mario who chases you does appear as a Wonder Effect.
- All Jossed. It's just Bowser Jr.
Assuming the trailers don't just feature an unfinished UI, this looks to be the first game in the series without level timers; it would be a shame not to feature levels that take advantage of this and challenge the player with long, intricate endurance tests, or perhaps levels that are maze-like and require more sophisticated puzzle-solving than would previously be feasible. Probably not that many - it'd still need to be accessible for younger players - but perhaps some boss levels and/or an extra-difficult bonus world will focus on these.
- Confirmed. There are levels long enough to feature more than one checkpoint.
- Perhaps he could function as a secret postgame character in the same vein as Rosalina in 3D World.
- The only potential issue with this is that Donkey Kong has his own 2D games. So Nintendo might view putting DK in a 2D Mario game when he already has his own 2D platformers as a bit redundant.
- That is of course assuming we get another Donkey Kong Country entry.
- Jossed. Donkey's Kong's not in this game.
- That is of course assuming we get another Donkey Kong Country entry.
- If the elephants on the fountain allude to this form's abilities, Nintendo would need to pick out five other large animals that are known for sucking up and spraying water. Could be convincing if anyone were to list enough fitting alternatives. And the power-up would probably have to be elephant-themed for all characters, since Tanooki Mario and Kitsune Luigi both use the Super Leaf, and it'd be annoying if each character could only collect their corresponding fruit.
That last part also seems pretty loaded if it's implying that Peach and Daisy's elephant forms would be inherently sexual. Mario's elephant form is already being sexualized, even though he's a man. Conversely, Miyamoto wanted Peach to be playable in Super Mario 3D World because "cat women are sexy". As with elephant Mario or Cat Peach, even if a few people find the concept titillating, there's no need to steer clear of the idea when it probably wouldn't be sexualized at all in-game. - Jossed. All characters gain elephant forms from the Elephant Fruit.
- Jossed. Luigi's elephant form is near-identical to Mario's elephant form.
- Jossed. It's just the Flower Kingdom.
- Jossed. This game was in development at the same time as the movie, and the developers didn't know much about it. They did however make the animations more expressive out of assumption on what the movie would look like.
- In said true final boss fight, he'll use every single power-up in the game against you, such as turning giant with a Super Mushroom, or into a giant elephant with the Elephant-power up, and in the final phase, he'll use a wonder flower to turn himself into a giant butterfly-themed Eldritch Abomination.
- Seemingly Jossed. The Direct showed That The Caterpillar, whose name was revealed to be Prince Florian, had invited Mario, Luigi, Peach, Daisy and so on over to the Flower Kingdom. However Bowser showed up and wanted to take over Prince Florian's castle.
- Jossed. Bowser's the villain without any twists.
- Seemingly Jossed. The Direct showed That The Caterpillar, whose name was revealed to be Prince Florian, had invited Mario, Luigi, Peach, Daisy and so on over to the Flower Kingdom. However Bowser showed up and wanted to take over Prince Florian's castle.
- Jossed. The only returning powerups from past games are the Fire Flower and Starman.
- As an alternative to this, maybe the talking flowers that accompanied you throughout the game won't be able to access this end game world, and are replaced with an Evil Counterpart set of flowers that do the things described above. Maybe make them roses with thorns.
- Or perhaps they just won't show up at all, making the levels eerily silent and lonely.
- Confirmed with the first four levels in Castle Bowser where they're entirely absent. But Bowser's Rage Stage brings them back but with a distorted voice.
- One of the bonus levels in games does have red talking flowers, but they're just as friendly as the regular flowers. Not jossed quite yet, likely a variant.
- Confirmed, but in a weird way - rather at than the end of the game or a particularly difficult level, the Talking Flowers suddenly become nasty and hostile as an added consequence of the Wonder Effect in The Desert Mystery.
- If this is not the case, then it’s just Hitbox Dissonance on the Bullet Bill’s part.
- Confirmed, as while Yoshi can't take damage, he still reacts to damage without getting hurt.
- Seemingly jossed for the "Can't use power-ups part", the official website states that all playable characters can use power-ups.
- Actually confirmed. The August Direct confirms that Yoshi can't use power-ups, meaning that it must have been a mistake on the writer's part. That said, he still seems to be able to use Wonder Effect transformations, as official artwork exists of a Goomba with a Yoshi Egg shell on his head alongside the other characters' Goomba forms.
- Confirmed. The Super Mario Wonder Direct stated that Yoshi can’t take damage.
- Jossed: Yoshi seems to not be able to use power-ups at all.
- Horse Mario
- Runs faster and can perform a headbutt attack, as well as allowing players to ride on him
- Electric Mario
- Can shoot electric shots and perform an electric whip attack in a similar vein to Earthworm Jim's whip attack.
- Kangaroo Mario
- Can perform a high vertical jump that allows him to reach higher platforms.
- Sumo Mario
- Can use several sumo wrestling-type moves, like slamming into the ground with his foot, causing a shockwave, at the cost of jumping lower and moving slower.
- Giga Mario
- A Refitted for Sequel take on the scrapped Giga Mushroom from Bowser's Fury, in that it's a powered-up Mega Mushroom that allows you to cause even more destruction.
- Bird Mario
- Can jump 3 times in the air as well as glide.
- Smash Mario
- Gives Mario similar abilities to his Super Smash Bros. counterpart.
- Wolf Mario
- Can slash at enemies with his claws and runs faster.
- Zombie Mario
- A reimagining of the zombie costume in Super Mario Odyssey. Mario will walk slower in this form, but can also use his head-ax as a weapon by throwing it at enemies, God of War (PS4)-style.
- Laser Mario
- can shoot laser blasts to the left and right only, essentially turning the game into a Run-and-Gun.
- Jet/Rocket Mario
- Sort of a mix of the Propeller Mushroom and the Jet Hat from Wario Land: Super Mario Land 3
- Wind Mario
- Can throw blasts of wind that push enemies back
- Ninja Mario
- Can stick to walls without sliding down them and can throw shuriken and/or use a sword
- Blooper Mario
- Enhanced swimming and the ability to attack with ink
- Semi-Confirmed, as there is a badge that does give enhanced swimming but its not a transformation.
- Enhanced swimming and the ability to attack with ink
- Dirk Drain-head Mario
- Can throw plungers at enemies Ghosts And Goblins-style, as well as stick to walls with his plungers and Double Jump. Mario's Dirk Drain-head form will resemble the latter's sidekick Snakey, while Luigi's will resemble the actual Dirk Drain-head (albeit a lot less muscular). The rest of the characters will receive unique designs. It would be a funny way to make Dirk a Canon Immigrant.
- Centaur Mario
- Another Refitted for Sequel power-up (this time based on the scrapped centaur power-up from Super Mario Bros. 3). Can throw spears at enemies, run faster, and use his spear to glide.
- Clock Mario
- Can slow down time. Honestly, it's baffling that no such power-up exists in any Mario game so far.
- Actually it does exist in the form of Super Mario Bros. 2's Stopwatch. Though that one stopped time entirely, rather than slowing it down.
- Can slow down time. Honestly, it's baffling that no such power-up exists in any Mario game so far.
- If you look closely at the first level shown in the trailer, the Mushroom Kingdom can be seen in the distance, making this a possibility.
- The August Direct reveals that there seems to be a short playable section before the opening cutscene, meaning the possibility is even higher now.
- Jossed. The game starts with the gang already in the Flower Kingdom.
- Mario, who is more famous for jumping than anything else, will turn into an elephant, one of the very few mammals that can't jump.
- Luigi, who is known for being a Lovable Coward, will turn into a wolf, a stereotypically scary animal. This wouldn't be that out of the blue, as he got a werewolf costume in a Halloween-themed piece of art.
- Peach, Mario's love interest who is much taller than him, will be a mouse, since 1. Elephants supposedly dislike mice and 2. Elephants are the go-to "big" animal and mice are the go-to "small" animal, reversing their height dynamic.
- Daisy, Luigi's love interest who is a lot tougher and more confident than him, will be a sheep, the most stereotypical animal for a wolf to hunt and overpower.
- Jossed, everybody has received elephant forms.
- The trailers seem to suggest the game will have more robust voice acting than the franchise's usual fare, and this would be a fun nod back to the film giving Charles Martinet several cameos.
- Jossed. Kevin Afghani is fairly new to the voice acting scene, with his only previous prominent role being Arnold in Genshin Impact.
- Most likely not all of them, as some of the badges seem to have elements of Self-Imposed Challenge and it's very likely some will be mutually exclusive, but a combination of several is definitely still on the table.
- Jossed. No such badge exists.
- This gameplay footage shows that most Wonder Flower segments will have unique themes, making this unlikely.
- Jossed. It's an original theme.
- Jossed.
- Jossed for the base game at least.
- All but deconfirmed already. The opening cutscene for the game syncs up with the level Welcome to the Flower Kingdom! (with the Mushroom Kingdom visible in the background), while Petal Isles is shown to have paths feeding into it from every world. It's more likely that it's segmented, with a few of its levels unlocking after clearing a certain part of a world (if not finishing it).
- While the tutorial part is tossed. The rest of the prediction is close. Bowser does technically corrupt the Petal Isles to change it's world map theme, though this doesn't affect the levels. Instead, the final levels take place within the castle itself.
- Confirmed. The Special World is a hidden world that can be accessed by finding the secret entrances in each world.
- Confirmed as of the demo. There is even an exclusive level you can play for managing to Game Over in the demo. Although we don't know if this level is in the full game.
- It helps that Super Mario 3D World did a similar thing, with its seventh world tricking you into thinking it's the final one due to it being Bowser's Castle, only for Bowser to reveal that the final world is actually Bowser's theme park.
- The area Yellow Yoshi travels through in the August Direct could be set on top of Bowser, given the similar aesthetic of the buildings and the green goo at the bottom of the screen.
- Another thing that helps is that the narrator of the August Direct stated "…And more" after revealing the 7 worlds.
- Jossed. Friendly-fire and player collision has been removed for this game. The Wonder Flower triggers this event, and every player partakes in the transformation until they can revert back. The Goomba form's weakness is you can't jump or run as the lowly mook.
- Jossed, it's the Super Mario Bros. lose life theme as seen in the demo. Managing to Game Over even plays the extended version like with World.
- Petal Isles' version will be funk-based.
- Pipe-Rock Plateau's version will be the one we hear in the trailers.
- Fluff-Puff Peaks' version harmonica-based.
- Shining Falls' will be A Cappella which some guitars mixed in.
- The desert world's variant will be banjo-based.
- The forest world will have a theremin variant
- The lava world's variant will be tribal drum-based.
- If there are levels taking place inside of the Bowser-Airship, the variant of the Wonder Flower theme that's heard there will be heavy metal-based and will be played in minor key.
- Seems to be Jossed. Judging by this gameplay, the Wonder Flower segments will all have unique themes.
- Jossed. Tatanga isn't in this game.
- Jossed.
- Jossed. Bowser never uses powerups.
- Jossed.
- The real reason for the game never getting DLC was likely due to it being exclusive to a poor-selling console at the time. It also technically did get DLC if you count Bowser's Fury.
- Pikmin 3 got DLC but not 3D World, so there's no excuse. And Bowser's Fury doesn't count as it came with the base game of the rerelease.
- Partially jossed. The heroes fly up to the top of Castle Bowser of their own will, but inside is a gargantuan Eternal Engine, and almost plays like a Band Land.
- Considering the settings only display voices for the flowers specifically, it seems unlikely that any other character will be fully voiced, even in cutscenes.
- Jossed. While there are cutscenes with dialogue, no characters are fully voiced aside from the Talking Flowers.
- Or it could be like Super Mario World where the story is told through text box narrations, this time at the start of each world instead of the end. Evidence to this is in the demo where a text box appears telling the player that the heroes have begun their journey.
- Confirmed. The game still has an Excuse Plot, but does have more story elements than the New Super Mario Bros. games, with most worlds having their own subplot, and a larger amount of character dialogue.
- Mario:
- Brian Hull
- Eric Bauza
- Roger Craig Smith
- SungWon Cho
- Billy West
- Chris Pratt
- It's highly unlikely that Nintendo would hire a celebrity voice actor for the games with how expensive it would be. Leave him to the movies.
- Pierre Tessier (the guy who voiced Mario in the French dub of The Super Mario Bros. Movie)
- Chris Diamantopoulos
- Luigi:
- Eric Bauza
- Tom Kenny
- Seth MacFarlane
- Mike Henry
- Jossed. Kevin Afghani, a relative newcomer to voice acting in games, voices both of the Bros.
- Active badges, which give Mario and friends unique moves in levels. This includes stuff like Luigi physics, gliding cap, and better swimming controls.
- Passive badges, which give Mario and friends skills passive skills in levels, like attracting coins, safely bouncing out of lava or cliffs once, starting the level in Super form, etc
- Handicap badges, which give Mario and friends Self-Imposed Challenges, like invisibility that averts Visible Invisibility, or being unable to stop running like in Super Mario Run.
Possible choices include:
- Reverting the power-up damage system to immediately shrink to Small form whenever you get hit while using Fire Flower, Drill, Elephant, or Bubble.
- Making Mario a one-hit wonder, even dying in one hit while under a power-up form.
- Double-jump
- Confirmed in the form of the Boosting Spin Jump badge.
- Power-up Magnet. There is already a coin magnet, so why not.
- Extended combo timer.
- Super Jump Punch.
- Allowing you to stick to walls for longer than normal. (similar to Flying Squirrel Mario)
- Adding a time limit that starts at about 30 seconds and can be replenished by grabbing coins.
- Dodge roll
- An Unexpected Gameplay Change from a 2-D platformer to a 3-D platformer, which could possibly work like flipping dimensions in Super Paper Mario
- Partially jossed. One of the Wonder Effects has you move on the background in 3D, but you can't jump or use Power Ups.
- Flipping gravity every time Mario jumps.
- Jossed, though the Wubba form can move on the ceiling.
- The Talking Flowers don't seem to do all that much aside from being very reactionary. Their reactions are ones that are expected from the players.
- The reason Bowser's use of the Wonder Flower was strictly beneficial for him, but it is a mixed bag for the heroes, is because it's controlled by thought. Notice in most levels, before you get a wonder flower there is a bit of Foreshadowing before you grab it. In Piranha Plants on Parade, a talking flower mentions that walking plants are almost as weird as singing plants, soon after you find a Wonder Flower and suddenly there are singing plants. In Bullrush Coming Through to get to the Wonder Flower you have to ride a Bullrush, then the Wonder Flower makes a massive stampede of them. The Wonder Flowers are taking the thoughts of the person who uses it, then exaggerating it and making it real, so because Mario heard that statement about singing plants, it's on his mind, he activates the Wonder Flower and because he thought of it, it's real, and that's probably why levels with themes have Wonder Effects with the same theme. For the effects with no Foreshadowing, it might just be a random thought that occurred to whoever touched the Wonder Flower, eg: what if I could walk on a wall? Because the heroes never realise how to control the Wonder Flower, they cannot stop the effects from being mostly random.
- Bowser turning into the castle makes sense with this. He wanted to be fortified so he could carry out his plan, and he needed to be mobile so he could have the Wonder Power and move to get more, and his clown car is mobile (likely why he brought it). A castle is Bowser's favourite type of fortress, so that would be on his subconscious. What happened is that Bowser thought of what he needed for his plan to work, and that caused the Wonder Flower to give him what he thought about, a.k.a. what he wanted.
- Bowser Jr. is a bit of an exception. He's a kid, so he shouldn't be able to control it that well, even if he does know how it works. But maybe he doesn't. Notice in each boss battle, the Wonder Effect isn't granted by a flower, but by the dark clouds around the castle, the same dark clouds coming out of Castle Bowser, so it's Bowser's Wonder Effect. Also, Bowser Jr. can do two Wonder Effects, but only those two. Since Bowser is getting stronger and gaining more Wonder Power, he probably has a bit more control over and is giving a limited amount of power to Bowser Jr., which Bowser Jr. has trouble controlling. In the first battle, his first attempt at manipulating size results in him shrinking and the heroes becoming giant, a pretty stupid move if he's planning it, but he's not. In the following battles, he tried one wonder effect, then another, but for his final life point, he switches between them. He doesn't know what Wonder Effect he can control, so he's experimenting with them at random, before he uses both to try to defeat Mario.
- Wario-themed levels including payable appearances by Wario and Waluigi.
- Space-themed levels featuring a playable Rosalina.
- City-themed levels featuring playable Pauline.
- Or possibly Donkey Kong if the developers want to cash in on The Super Mario Bros. Movie.
- Food-themed levels featuring the Koopalings as bosses
- Also, each of the Koopalings will have different effects and powers under the influence of the Wonder flowers
- Birdo as an easy playable characters like the Yoshis and Nabbit
- Certain Power-ups from previous games return
- Ice Flower
- Penguin Suit
- Cat Bell
- Super Acorn
- Propeller Mushroom
More of a joke theory, but the funniest possibility is usually the correct one, or something.
He just doesn't use them often because he has very little control over them and they'll often be as much of a threat too him as they are too whoever he's fighting.