Bumper

A bobbin, also known as a bumper, is one of the most iconic obstacles in the games. These objects make first appearance in Sonic the Hedgehog in 1991. The bobbins work similarly to pinball bumpers, as when Sonic the Hedgehog (or other player character) comes into contact with them, he will ricochet off them. Bobbins can be a nuisance, as Sonic can be stuck bouncing among bobbins; however; they can be used to advantage to propel the hero for further distance.

Description
In Sonic the Hedgehog games, bobbins are basically featured in casino-themed zones, Bonus Stages or even in Special Stages. Bobbin usually flashes after getting hit and bouncing off it is worth 10 points. In some games, bobbin will stop awarding points if the player hit it too many times. Because of this, each bobbin can award a limited number of points.

Bobbin's appearance changes many times thought the series, but usually it is described to have red background, blue center and in the center is yellow or white colored five-pointed star. This round symbol is used in other objects (see below).

Even the shape of bobbins has been changed few times in the series. In first Sonic games for Sega Genesis, Master System and Game Gear, it's been illustrated as a floating round object. After Sonic 3D Blast, Sonic Adventure and few later games, bobbins had been illustrated like flat, real life pinball bumpers, but it returns to floating round object form in Sonic Heroes. Even to this day, the object's shape is varied, possibly depending on if the gameplay has been 2D or 3D.

Sonic the Hedgehog (1991)
Bobbins first appear at Spring Yard Zone in 16-bit version of Sonic the Hedgehog, as they earn 10 points for bouncing them. In that zone, these objects usually occur in groups. (Bobbins can appear as common obstacles in the Special Stage and can be seen before Spring Yard Zone). This orb-shaped object is a red background, blue in the middle and has five-pointed star in it.

Bobbins also appear at Special Stages in 8-bit version of Sonic the Hedgehog. In the game, bobbins have same appearance like its 16-bit counterpart, although these objects are little larger than Sonic himself.

Sonic the Hedgehog 2 (16-bit)
Bobbins make its appearance in Sonic the Hedgehog 2, as they are featured in Casino Night Zone. Bobbins in the game have similar appearance, having a red background, blue in the middle, but it has now white five-pointed star, Also between red background and blue centering there's extra line, which flashes green and yellow. Bobbins also earn 10 points in the game, but soon stops giving points after bouncing to it several times.

Sonic the Hedgehog 2 also features more pinball themed elements, like hexagonals, triangles and blocks.

Sonic CD
In Sonic CD bobbins are featured at Collision Chaos, Special Stages and above last bottomless bit of Metallic Madness. In Special Stages they are more flatter and have similar appearance from the first game. In game's rounds, bobbins are more detailed looking, as their background is cubic ornaments with red and white colors and moves around. The centering of bobbins is colored blue and has yellow five-pointed star in it. Like in the first game, these objects are floating in groups.

Sonic Spinball
Although bobbins didn't appear in 16-bit version of the game, Bobbins do appear at exclusive Egypt-themed bonus stages in 8-bit version of Sonic Spinball. In the game, bobbins are larger than Sonic himself, like in the 8-bit version of Sonic the Hedgehog.

Sonic the Hedgehog 3 & Knuckles
Bobbins make their appearance in Sonic the Hedgehog 3, as bobbins are featured in Carnival Night Zone and Special Stages. These different bobbins are white with a red star in the middle this time around but they are still the same. Like in Sonic the Hedgehog 2 bobbins give 10 points until they stop doing this after bouncing several times. In Carnival Night Zone, there's also ones, that are rotating around two or three ones. In Special Stages, bobbins bounces the player to walk backwards.

Sonic & Knuckles has two different looking bobbins in two different Bonus Stages, although they work same as others. First one exist Slot Machine one (20 rings is required to get in it), which is smaller, having big red background, yellow between line and blue center with white five-pointed star. Second one can be found rarely from Magnetic Orbs Stage (50 rings is required to get in it), as its shape is similar to Sonic the Hedgehog 2 ones, but the background of them is green, red between line, pink center with white five-pointed star.

Sonic Drift 2
Bobbins appeared in Casino Night track in Sonic Drift 2, which tries to bounce the player out of track. Here bobbins look more like orange Springs with star above it.

Knuckles' Chaotix
In Knuckles' Chaotix bobbins are included in both Bonus stages and Special Stages, where Bobbins are moving around or rotating in one direction. It also appears few times in normal gameplay (for example first Eggman fight). Bobbin's appearance is basic as its background is blue, center is red and yellow five-pointed star.

Sonic 3D Blast
Bobbin's appearance in Sonic 3D Blast is slightly different in every zone as it is more flat, green glowing ball at Rusty Ruin Zone, flat, red and yellow colored ball at Spring Stadium Zone or flat, light blue glowing ball at Diamond Dust Zone. In the game, bobbins don't give points nor it doesn't bounce very far, unless the player is in full speed.

Sonic Blast
Bobbins appear briefly in Sonic Blast, only being featured at Special Stages, where it will bounce the player backwards like in Sonic the Hedgehog 3. Bobbins in this game look more like real-life bumper, which has above red background, blue center with yellow five-pointed star in it.

Sonic Adventure
Bobbins appeared at Sonic-themed pinball section of Casinopolis in Sonic Adventure. In the game it has Sonic the Hedgehog 2 appearance, but looks more like real-life bumper and as bouncing few times, the player can earn a one rings per hit.

Sonic Advance
In Sonic Advance bobbins are featured in Casino Paradise Zone. Its appearance looks like one from first Sonic the Hedgehog game and acts like it did in first games.

Sonic Heroes
Bobbins make its appearance in Sonic Heroes, usually as floating, spherical pinball bumper. Bobbins have green surface and front side is colored black with light green five-pointed star. Bobbins are featured in Casino Park and Bingo Highway, as it can be found in pinball tables and outside of them. In outside of pinball sections, the speed characters can bounce on them more safety by using Homing Attack.

Sonic Pinball Party
Bobbins appear at almost every Sonic board in Sonic Pinball Party. In the game, bobbins give points and have exactly the same appearance from Sonic Advance.

Sonic the Hedgehog 4
Bobbins returns at Casino Street Zone and special stages in first episode of Sonic the Hedgehog 4, as they are exactly how they are from Sonic the Hedgehog 2. Due the different rotations on game's physics, bobbins don't bounce the player very far and its easy keep direction forward after bouncing.

Sonic Generations
Bobbins also returns in Nintendo 3DS version of Sonic Generations as it is featured in Casino Night Zone. and acts like in the original zone of Sonic the Hedgehog 2. The only times bobbins appear in console versions is DLC pinball mini-game of Casino Night (where Bobbins are like real-life bumper looking) and classic Sonic's challenge of Crisis City, which features Vector the Crocodile as ally where Bobbins are flat and floats in group.

Sonic the Hedgehog Story Comic
Bobbins appears briefly in Sonic the Hedgehog Story Comic Volume 2 story "Clash!! South Island" as during the journey of saving animal friends, Sonic enters to the Sparkling Zone, he accidentally slips on a slide and is thrown into the pinball arena. He then gets bounced back and forth between the many bobbins, only being confused. After that he lands to the ground, until one second later Crabmeat and Newtron tries to attack him, but got destroyed by Sonic.

Adventures of Sonic the Hedgehog
In the Adventures of Sonic the Hedgehog episode Attack on Pinball Fortress, different coloring Bobbins are featured at Dr. Ivo Robotnik's new lair, Pinball Fortress. Bobbins are usually set to the pinball section as Sonic, Sergeant Doberman and Wes Weasely keep bouncing them countless times to get through giant pinball table. Bobbin symbols also can be seen at fortress' background.

Bobbins also appear in episode Robotnikland where objects are part of large pinball table called "Pin-Ball Blizzard" at park that Robotnik has taken over. Sonic gets bounced bobbins and other gimmicks while Robotnik is earning points from the pinball game. After while Sonic starts earning points for himself and such Robotnik sends Scratch and Grounder to the pinball table to stop Sonic. However the badniks assault fails and they got stuck to the pinball, bouncing around bobbins and other pinball gimmicks.

Symbol
The yellow five-pointed star on a blue circle among a red background or in an annulus (sometimes white star, usually star overlapping the blue circle) is a common symbol in the series. In Sonic the Hedgehog 2, the symbol of a star in a red annulus is the main feature of Star Post's replacing the lamppost that were the previous check-points in Sonic the Hedgehog. Also the Badnik Crawl has shields fashioned like bobbins that protect them, functioning just like the real thing.

Ever since springs have been rendered in 3D games they have been red, supporting the star-on-blue-circle bobbin design on them where Sonic jumps from. Also since Sonic Adventure 2, large red balloons with the bobbin symbol are on certain stages, once popped you get a bonus item as well as useful to gliding or flying characters who need a bit of lift.

In Sonic Heroes Check Points have been redesign as pillars of blue light with gold stars in red circle. The colors and design also resemble the bobbin symbol. These checkpoints are favored for Nintendo DS side-scrolling games.

The recently introduced Red Rings have stars set in their centers.

Trivia

 * Bobbins have unique sound effect, which has been used in many games where object has been appeared. However there's been exceptions that has used different sound effect such a Sonic CD, Sonic Spinball and Sonic Adventure.
 * Few enemies or even bosses used bobbins as shield such Crawl and Robotnik's Bobbin Walker. Although many of them uses spring sound effect which can lead to confusion, which object possibly these enemies use.