For this I'm going to presume the gameplay is similar to Smash with the specials.
Job 8: Sonic Playstyle
Basic Playstyle:
Sonic, as the resident speedster with an in your face attitude seems to naturally fit the role of a rushdown character, constantly applying pressure via his speed.
Sonic is adept at attacking from all angles with overwhelming speed. He can curl into a ball and attack from above or in front, from below he has the ability to slide on the ground, kicking opponents up from below and setting up for combos.
Gameplay wise, Sonic is
not a good swimmer, so any water hazards are best avoided as the Blue Blur as he has super drowning skills compared to the rest of the roster.
Sonic's Basic moves:
Sonic's basic moves I feel should include punches and kicks from Sonic Fighters, but with a heavier emphasis on kicks due to his far stronger legs.
Overall Sonic probably should deal less damage than the average fighter(outside his specials) for both balance and combo encouragement.
His shield is the barrier item you can obtain from the monitors. I feel custom shields would be neat here, and there's still plenty of options for other Sonic shields should we need them for items later down the line.
Special attacks:
Neutral Special: Spin Dash
Probably Sonic's most iconic move.
By charging his spin, Sonic can charge himself into a powerful blue ball of spikes before launching himself forwards at terrific speeds. The player can change direction whilst in the ball, and can attack out of the ball creating combo potential.
Down Special: Bounce
Best used in the air Sonic can drop down suddenly, smashing into anything below him. Much like Yoshi and Bowser's respective Bomb attacks, when performing this Sonic will any forward momentum he has and shoot straight down. It differs from the reptiles in Smash, by allowing Sonic to bounce directly back up higher than he was before. This move is based off the effects of the Bounce Bracelet Sonic uses in Sonic Adventure 2.
Side Special: Sonic Storm
A move used in Sonic Battle, Sonic revs up like he's going to spindash, but upon charging enough he unleashes a massive Sonic boom explosion that propels him in the opposite direction. The 'boom' is a projectile blast of air that can knock opponents flying, but Sonic can also use this ability to recover from falling off stage, as the move can be performed in the air. Sonic is however stuck in his curled up ball mode until he makes contact with solid ground from this move so use it sparingly.
His up Special I'm torn on as it depends on whether Tails makes it onto the roster or not:
If Tails isn't added:
Up Special: Miles "Tails" Prower
Sonic's best buddy, loyal sidekick and the brains of the outfit is here to lend Sonic a helping hand, just like in the old days. Tails can helicopter Sonic to safety with great vertical and horizontal speed, but he tires out quickly.
Anything that touches his spinning tails will take damage, but attacking his hands will cause Tails to accidentally drop Sonic.
If Tails is added:
Up Special: Orange Rocket
Sonic calls upon the power of the orange wisps from Sonic Colors transforming him into an Orange Rocket. He shoots directly upwards. Anyone that should get in the way of the Orange Rocket will get severe knockback, but Sonic is left briefly vulnerable when the Wisp power wears out at the top of his ascent, allowing opponents to take advantage of this. The vulnerable state wears off after a while, allowing Sonic to move into a Sonic Storm to aid with his horizontal recovery. Kind of like a reverse Luigi, Sonic should use his Orange Rocket and THEN the Sonic Storm to prevent him from entering a helpless state.
All Star Move: Super Sonic
It couldn't really be anything
but Super Sonic, right?
After the seven Chaos Emeralds spin around him, Sonic transforms into Super Sonic, and charges towards his opponents at blinding speed several times, knocking them higher and higher before launching a barrage of golden energy blasts from his hands which home in on the opponent, knocking them into the blast zone.
Yes, I know it's
very Dragonball, but Sonic has done it in his games.
Misc:
Idle animation:
Sonic taps his foot impatiently, and looks directly at the player.
Entrance animation:
Sonic speeds on screen, screeching to a halt.
Taunts:
Taunt 1: Sonic spins a ring on his finger.
Taunt 2: Sonic performs a Super Peel Out(that move where his legs run rapidly as he runs on the spot - See the palettes below.)
Taunt 3: Sonic lays down on the ground, hand supporting his head as he takes a bite of a Chili Dog he produces from behind his back.
Victory Animations:
Victory animation 1: Sonic bounces on top of an animal capsule, freeing the animals (Ricky, Pocky, Flicky, Rocky, Cucky, Pecky and Picky) from the capsule.
Victory animation 2: Sonic spins past the Goal Plate with Eggman's face on it, as it spins several times before slowing and revealing Sonic's face. He runs back into frame and leans on it, waggling a finger at the viewer.
Victory animation 3: Sonic is relaxing in a checkprint hammock as he spins a ring on one finger. "Too easy"
Palette Swaps:
Just like with the above Tails mention, I'm not sure exactly who is making it to the roster from Sonic yet.
With limited spaces in the roster for Sonic cast members, Shadow may not get to appear as a playable so I felt it was important to give Sonic a Shadow themed alt at least. If Shadow does get in, maybe we'll replace it with a Knuckles themed one...or if both get in...I dunno...Espio?
Edit: Added an entrance animation which I completely forgot.