From Sonic Retro
The Spring (スプリング), also referred to as a Springboard is a common gimmick that has appeared in many games in the Sonic the Hedgehog series that gives the player a sudden boost in a certain direction when they get in contact with one.
Types of springs
In the 2D Sonic games of the 16-bit era, springs can face any of the 8 main directions, and they come in two colors: yellow and red. Red springs are usually more powerful than yellow ones. They have been thoroughly present in almost all the zones from Sonic 1's Green Hill Zone to Sonic & Knuckles' Death Egg Zone.
In Sonic 3D there is only one kind of spring instead.
In the 8-bit games, most of the springs are actually drawn in the level layout itself instead of being sprites because of the low sprite limit of the Sega Master System and the Sega Game Gear; because of this, they're not animated unlike their 16-bit counterparts. Furthermore, their color is likely to change according to the palette of the level they're placed in (for example, the springs in Sonic 2 (8-bit)'s Under Ground Zone are gray, while the ones in Sky High Zone are green). However, despite the sprite limit, in Sonic Chaos and Sonic Triple Trouble a spring object exists. These spring objects are normally invisible, hidden in the ground or on the top of a palm tree or other scenery elements, and they pop up, complete with the springing animation, when Sonic comes in contact with them. Due to the high number of color variations, the springs pictured below don't cover all the kinds existing in the 8-bit games.
|Sonic 1 (8-bit)|
|Sonic 2 (8-bit)|
|Sonic Triple Trouble|
In Knuckles Chaotix, along with yellow and red springs, there are also blue springs which are even more powerful than the red springs. These are used to get to high heights with the Combi system.
From Sonic Adventure onward, the springs are now only one type of spring, a red spring with a star on it. The spring power varies with each individual spring.