I know many people had ideas for what SA3 should be, but here's my ideas:
I'm using Unreal Engine as the engine to make the game on.
I will base the character gameplay off of Project Hero, Sonic Adventure/2, Sonic Unleashed, and Sonic Generations.
There will be 2d sections, but ONLY for wall jumping.
Knuckles will have the radar of SA, which'll remove some difficulty, but it won't be too long and grating to find important objects.
For some characters, I will change some of the stage to accommodate their gameplay.
I also plan on making custom medals. They will be like the Unleashed medals, only they will have a gold border, with the medal itself being silver, with the symbol of the wind. It'll have a metal texture.
The Adventure HUB Worlds will work like Unleashed, with Earth being the point of the HUB Worlds. Each HUB world will have a symbol or a flag, and the hub worlds would be:
Central City (United Federations Flag)
Mystic Ruins (Echidna Flag)
Angel Island (Master Emerald symbol)
White Acropolis (Snowy Eggman symbol) (White Acropolis needs some love)
Kalani Village (Wind Flag)
Egg Carrier MK III (Eggman Empire Symbol)
Makani Temple (Corrupted Wind symbol)
The bosses will be:
Egg Hornet MK II
Egg Buzzard (Final Boss)
Vindicator II (Final Boss)
Mesaru (Final Boss)
Full Power Makani.
The gameplay will vary for each character.
Homing Attack- The essential Dreamcast/Modern Sonic
Spin Dash- An essential to a Sonic Adventure Game
Light Speed Dash- Unlike in Adventure, it'll function how it does in later games, with you instantly going through rings.
Wall Jump- That's an essential element to the game as well, as some parts of the stage requires wall jumping. In some cases, like 06, you might even need to jump wall to wall.
Sliding- That's a must have to get through many narrow entrances.
Drift- That is also a must have if you go through a level with curves.
Bounce- Unlike Adventure 2 and '06, the bounce is going to be in Sonic's natural moveset.
Stomp- He will also need this in order to activate switches, or go down boxes.
Quick Step- Again, essential.
Miles "Tails" Prower
Flight- Using his twin tails, Tails can propel himself into the air. However, I will add a meter to indicate when Tails' stamina is being lowered.
Rapid Tails Attack- As I like to dub it "The Twin Tail Tornado". With this, he can spin his tails around continuously, to the point where he looks like a yellow tornado.
Arm Cannon- Once he gets an upgrade from his lab, Tails can use his Arm Cannon to blast through enemies. The targeting system works like in Unleashed, where you press a certain button to kill enemies
Knuckles the Echidna
Knuckles Glide- As usual, Knuckles can glide, hitting enemies along the way.
Climb: Using his spikes on his hands, Knuckles can climb through walls.
Punching: Knuckles can punch enemies, usually taking 3 hits to destroy them.
Drill Claw: Knuckles can dig underground, useful in finding an object vital to the plot. Once he has the shovel claws, he can instantly dig through anything.
Air Necklace: Since some of Knuckles' stages are underwater, it is optional for Knuckles to go to Tails' workshop and get the air necklace. With this, it allows Knuckles to breathe underwater.
Hammer Punch: When he jumps, Knuckles then punches the ground, creating a shockwave that kills enemies. Depending on how high the jump was, it can range from being near ineffective, to unstoppable destruction that can DESTROY wildlife. (To get to the highest level of destruction, you need to jump from a high area, THEN do the hammer punch)
Shadow has the same moveset as Sonic, with the main difference being that Shadow possesses Chaos Attacks.
A chaos bar will be added for the Chaos attacks, but using them will drain the bar, and the only way to refill it is fighting enemies, which'll give you 5% of power for each hit.
Chaos Control (S): Using that technique, Shadow can teleport to a certain point in a level. It takes up 50% of the Chaos Bar though.
Chaos Control (T): Using this technique, Shadow can stop time for about 35 seconds. However, this will also take up 50% of the Chaos Bar.
Chaos Spear: Using this technique, Shadow can create spears of pure Chaos Energy. This takes up 5% of power.
Chaos Blast: Taking up 75% of power, Chaos Blast allows Shadow to glow red for 10 seconds, then if you successfully do a QTE where you press B 30 times, then the blast will occur. Depending on the EXP you collect, Chaos Blast can start out being a bit moderate, to half the power of a Nuclear Bomb.
Rouge the Bat
Rouge has the same moveset as Knuckles, In that she can Fly, Climb, Punch, and dig through walls/ground. However, she differs in terms of combat.
Double Jump: Rouge, due to her athletic practice, can double jump, allowing her to reach places where the others can't.
Consecutive Strikes: Rouge, like Shadow in '06, uses the Chaos Attack, only without the Chaos Energy to enhance it.
Bombs: When the need arises, Rouge can place bombs onto a wall/door. Once she does, it takes 5 seconds until it explodes, along with the item it's attached to.
Hover: Using the propulsion systems on his back, Omega can hover to another location for a while, until he lands on the ground.
Blaster Arm: Omega's main weapon, the Blaster Arm, shoots energy beams that instantly kill enemies. Like Tails, it has the same targeting system as Unleashed.
Machine Gun Hands: Omega can switch his arms for miniguns, shooting enemies for about 45 seconds at most until it recharges, which takes 3 minutes.
Flamethrower: Blaster Arms aren't the only things Omega keeps in his wrists. He also uses a flamethrower to burn enemies.
Strength: Because he's the ultimate E-Series robot, Omega can lift objects that no other E-Series robot can.
Those are ALL the characters' movesets.
Sonic and Tails will be playable on Sonic's Story. With the appearance of Amy Rose for one level.
Team Dark is on Shadow's Story.
Knuckles is the only playable character in his story.