So this is my draft of how Captain Toad would play:
I'd be very appreciated if you gave feedback.
Playstyle:
Captain Toad is slow and cannot jump high at all, and his attack speed is mediocre.
However, he gains his mobility elsewhere, namely through his Specials and Smashes.
His specials are Tracker Contraptions, special contraptions that make him faster, make him jump higher and can give him new attack strategies.
Think of the contraptions as if they're Monado Arts: The best at their job, but bound to a specific situation, or in this case, location.
While Captain Toad can't to much on his own, he can traverse the stage very efficiently through the use of his contraptions, perhaps even faster than the other characters!
Now he can attack the opponent like any other character can.
A good Captain would track his way through the stage, setting up his killer apps on the right places, so he can get anywhere.
Neutral Special:
Super Pickaxe
Captain Toad stretches it's arm backwards in its backpack and stretches them out forward again with a Pickaxe in his hands.
The Pickaxe breaks every contraption Captain Toad makes and deals 10% damage om the intial hit with high knockback
If the button is held, Captain Toad keeps swinging the Pickaxe up and down, dealing 5% damage per hit with medium knockback, still breaking any contraption.
This move is key in mastering Captain Toad, as this move is the key to mastering his contraptions.
While opponents can use the contraptions too, Captain Toad can destroy the contraptions and the master plan of the opponents with this move.
Destroy minecarts that are abused by Rushdown character, destroy propellor platforms that opponents use to recover and even destroy mushroom platforms that opponents camp on!
Side Special:
Minecart
Captain Toad takes his backpack and walks while shaking it up and down.
As long as the button is held, little pieces of minecart track fall out, making the Captain surprised.
These pieces of tracks deal 2% damage with no knockback, so you could potentionally combo the opponent
When the button is released, a minecart falls out.
This minecart deals 20% damage and kills at 140%
After the minecart is dropped down, it will drive around on the track on itself at the speed of Bowser Jr. (Still trying to find a more appropriate speed) like Gogoat.
The minecart acts as a platform and can be rode.
When the Minecart hits an opponent in this state, it deals 5% and hits opponents up slightly.
Only one minecart can be up per time and the move will do nothing when used when an old Minecart is up.
The Minecart is on-stage twice as long as Pac-Man's Hydrant
The Minecart acts as a substitute for Captain Toad's low speed and as an obstacle for the opponent.
The player can choose for a short track that blocks a specific part of the stage, or for a stage-wide steaming hype-train that Captain Toad can enter.
Up Special:
Propellor Platform
Captain Toad curls up in a ball all scared, when suddenly a Propellor Platform rises him diagonally upwards at the height of Captain Falcon's Up B and at the trajectory of Pit's Up B.
Poor Captain is afraid of heights, so he's nailbiting during the whole ride, so he can't attack during it.
The facing-side of the platform has a hitbox that deals 5% damage and medium knockback.
The platform will travel back to the intial position where the platform stays out for a while and can be made rise again by pressing UpB, repeating the cycle.
Only one propellor platform can be up at the same time.
The Platform is on-stage as long as Pac-Man's Hydrant.
Down Special:
Turnip Turret:
Captain Toad shakes its backpack up and down, creating a Turnip Turret.
The Turnip Turret shoots turnips every two seconds in spurts of three.
These turnips are shot in a straight line and deal 2% damage and deal low knockback, travelling half of Battlefield.
Sometimes, instead of shooting a spurt of three turnips, the turret shoots one big turnip that deals 10% damage, but travels as slow as Falco's laser.
When Captain Toad is close to the turret, the turret acts more like Auto-Reticle, "homing in" on opponents.
Only one Turnip Turret can be up at the same time and the move will do nothing when a turret is already on the field.
The Turret is on-stage twice as long as Pac-Man's Hydrant.
Smashes:
Side Smash:
Captain Toad holds his open backpack above him and looks at it.
Too bad for the Captain, a Clear Pipe Cannon comes out and traps Captain Toad
While Captain Toad holds his hands for his eyes, scared for the ride, the clear pipe cannon shoots him straight ahead.
The Captain spins around while being shot, dealing 15% damage total and kills horizontally at 150%.
Captain Toad is shot the length comparable to the lenght Mega Man's forward smash travels.
Up Smash:
Captain Toad looks at a red dot on the ground, looking curious.
Just as he wants to touch it, it is revealed to be a mushroom platform and it grows giant quickly, taking Captain Toad with him.
Captain Toad curls up in a ball and after the mushroom is full-sized, Captain Toad admires it.
The top of the mushroom is a rounded square with the width of a Battlefield platform, deals 10% damage and heavy upwards knockback.
The stem of the mushroom is Ganondorf-sized, deals little damage and horizontal knockback
The sweetspot, killing at 120%, lies at the middle of the mushroomtop.
When the move is done, it is revealed that the top of the mushroom is in-fact a trampoline, letting Captain Toad jump twice as high when jumping on it.
But jump quick, because the mushroom dissapears in a little three seconds.
Down Smash:
Captain Toad slams his backpack in front of him, looking content with his strenght.
This "attack" deals a pathetic 5% damage and light downwards knockback.
However, a clear pipe the lenght of 1 and a half Battlefield platform breaks out of his backpack.
This attack deals 10% damage and medium knockback.
After the attack is done, Captain Toad breaks through the pipe and can travel to one of the two sides.
Then the pipe dissappears
Jab:
Captain Toad unties his backpack and shakes it up and down repeatedly.
Forward Tilt:
Captain Toad gets very scared of the nearing opponent, and hides behind his backpack as a last reflex, pushing it forward as if it was poisonous.
He doesn't even look at the opponent getting hit!
The move does 6% damage and decent knockback.
Up Tilt:
Captain Toad, wait, Captain Toad does nothing with this move!
Instead, a Piranha Plant breaks out of his backpack, biting opponents.
This attack deals 8%, but little knockback, making it eglible for comboes.
Captain Toad then notices something and decides to look back, but then the Piranha already disappeared.
Down Tilt:
Suddenly, a crop comes above ground.
Captain Toad decides to pluck it, dealing 3% damage to nearby opponents, but no knockback.
When he has plucked the reward, he dumps it onto opponents, dealing 5% damage and differing knockback
Captain Toad can namely pluck different rewards, all dealing different knockbacks.
The diamond has the highest knockback, killing at 140%, the turnip is somewhat weaker and deals medium knockback and the coin is the weakest with low knockback, but acts as a multihit attack as it spins.
Dash Attack:
Captain Toad gets dizzy, indicated by the swirls around his head, and spins around four times.
The backpack turns into a hitbox.
There's one strong, intial hit when Captain Toad starts spinning, dealing 10% damage and killing at 130%, after that the move turns weaker.
During this time, the backpack deals 5% damage and the move kills at 160%
Neutral Aerial
A diamond flies out of Captain Toad's backpack, arcing over Captain Toad's head, who catches the diamond.
Too bad for Captain Toad, the weight of the diamond drags Captain Toad along, which causes Captain Toad to spin around.
After two spins, that deals 8% damage each with each spin and medium knockback, Captain Toad drops the Diamond back in his backpack.
Forward Aerial:
Captain Toad unties his backpack and swings it forwards with both hands.
Deals 10% damage with great knockback.
Back Aerial
Up Aerial:
A power star flies out of Captain Toad's backpack.
Luckily for him, he manages to catch the star after it bounces on his hand three times.
These hits deal 2% damage and little knockback.
The real star here is the fact that the Captain uses the newfound star to attack opponents, hitting them with the top "spike" while he holds the star at it's bottom "spikes"
This attack deals 7% damage and heavy knockback, potentionally Star KO'ing opponents that are caught very high.
It's Captain Toad's best kill move, but can only be landed with smart use of his contraptions.
Down Aerial:
Captain Toad does nothing in this move!
His backpack however, breaks from all the weight.
This causes a Mega Turnip the size of Bowser Jr. to fall out and damage opponents for 9% damage.
The Turnip falls to the ground rather quickly and dissappears when it hits the ground or a shield.
The Turnip also deals medium upwards knockback.
Grab:
A Clear Pipe arises from the ground, capturing opponent's inside.
The grab is not the fastest, but makes up for it for the utility of the throws.
Pummel:
Captain Toad memorises this Clear Pipe as the Clear Pipe that got him in the Sprixie Kingdom.
He also remembers that Mario and Luigi fixed it with their hammers and comes to the idea to hammer the pipe.
Captain Toad doesn't have a hammer though and instead hits opponents with his Pickaxe.
The animation resembles the intro of 3D World, switching sides of the pipe every hit.
Forward Throw:
Captain Toad pushes the Clear Pipe to the direction chosen, causing the pipe to bend and launch the opponent that way.
The throw isn't his strongest, but suffices as a way to get opponents off stage.
Back Throw
The Clear Pipe sprouts a cannon, scaring Captain Toad, and launches the opponent backwards, which causes Captain Toad to clap and jump up and down.
And for a very good reason, since this throw is a very strong KO move, killing at 130%
Up Throw:
Captain Toad decides to look down the pipe to see if something is coming upwards.
We as Mario fans know that when there's a pipe, there's a piranha plant.
But Captain Toad doesn't, and gets scared by the Piranha Plant that comes up, damaging opponents for 14% damage in a 4-hit bite combo, before ending with a last bite for decent knockback.
Too bad Captain Toad doesn't look until the move is done.
Down Throw:
Somewhat less dangerous than the Piranha Plants are the Fuzzies that inhabit the Clear Pipes.
One of these comes up and hits the opponents.
It doesn't do much damage or knockback and only throws the opponent right in front of Captain Toad, standing behind the pipe.