The Classic Gameplay Paradigm is a technical document about the gameplay mechanics of what are considered "Classic" Sonic games attempting to understand in the simplest of terms how they function from a design standpoint. Games considered under this are: Sonic the Hedgehog 1 (16-bit), Sonic the Hedgehog 2 (16-bit), Sonic CD, Sonic the Hedgehog 3, Sonic and Knuckles, Knuckles Chaotix, and Sonic Mania.
Note that things like music, art style, and story will be left out as this document is focused purely on the gameplay side.
The Classic games are at their core Two-Dimensional Platformers where the player moves toward a goal (usually to the right) while using the jump button to deal with various level terrain and enemies. Simple, genre perfected, but as is obvious, there is a great deal of difference between Sonic the Hedgehog and say Pitfall.
The basis of a Classic styled game movement of the character in relation to environment and player input. On a flat surface, the character will stay still until player input (as is the case with most platform games) moves the character either left or right. Movement will be accelerated over time so long as the input is held by the player eventually reach a base running speed that cannot be exceeded by player input alone. In order to reach top speed, assistance is needed from the environment with the most common cause being a downward slope. The character reacts not unlike a ball or roller coaster as speed and momentum are built (downhill) and lost (uphill) in cyclical fashion. It is this struggle of control between player input and the environment which give what I consider the base challenge of a Classic Sonic game. Being able to manipulate the character's speed and momentum based on its environment toward the goal.
The "Curling" state is a unique state available to the player which serves as an attack and as a way to influence character movement. It can be engaged as part of the standard jump (allowing some vertical height gain) or on it's own. In the curling state, the player is on the offensive, being able to dispatch most enemies with one touch while allowing the character to keep its momentum. In addition to this, certain environmental influences (such as slopes) have as stronger effect on momentum allow one to build or lose momentum faster.
The Super State is a special state accessible to the player after certain requirements are meant. In this state, player input is enhanced allowing the character to reach top speed without the help of the environment, the attack ability of the curling state is inherited, the effect of certain environmental hazards are nullified, jump height is enhanced, certain special abilities are accessible based on the character chosen.
Over time, additional movement options were added as ways to help the character traverse the environment and as a way to allow uniqueness amongst multiple characters. This allowed for changes in level design not possible before.
An additional input that allows the player to build momentum in the Curling state while in a stationary position before releasing said momentum either left or right. Useful in tight spaces.
Similar to the Spin Dash except the player isn't in the curling state.
An enhanced version of the curling state that produced a greater range of attack for a short period of time.
Similar to the Spin Dash except in the air and allowing the character to keep any momentum previously built.
A special ability that allows the character to move freely in the air for a certain period of time.
A special ability that allows the character to move left or right in the air with reduced gravity for a certain period of time.
A special ability that allows the character to stick to a wall for an indefinite amount of time and allows movement either upward or downward of said wall.
A special ability that causes the character to destroy certain walls by touching them.
A special ability allowing the character to jump from a wall in one of five directions.
Similar to climbing except faster
While in the air, it allows for a section jump either vertical, diagonal vertical, or horizontal.