Conveyor Belt

Conveyor Belts are long, infinitely moving assemblies seen within numerous games of Sonic the Hedgehog series. Based on two or more rotating wheels with a long belt set on to move endlessly between them, conveyor belts are recurrently featured in numerous machinery and air fortress-themed Zones. When Sonic or another playable character runs to the conveyor belt, his moving speed either heavily decreases or increases, depending on the direction the belt is moving. In some games, the movement speed of conveyor belts can also be slower or extremely fast.

Sonic the Hedgehog (1991)
In the original 16-bit version of Sonic the Hedgehog, conveyor belts are featured only at Scrap Brain Zone Act 2, where they can be found at halls and routes. These places also have dangerously inserted circular saws, swinging spiked balls and crusher tubes. Moving on conveyor belts is very difficult due the high speed and obstacles.

Conveyor belts are also seen in Scrap Brain Zone in the 8-bit version of the game with same name, where they are mostly floating in mid-air. In act 2, there is a large room with a lot of conveyor belts, which the player has to use to climb to the upper route.

Sonic the Hedgehog 2
Casino Night Zone and Metropolis Zone in Sonic the Hedgehog 2 are known to have singular conveyor belts floating in the zone. In the Metropolis Zone, conveyor belts sometimes have crushers above it. There is also a vertical conveyor belt at the mid-point of Wing Fortress Zone.

Conveyor belts have also been featured at Gimmick Mt. Zone in the 8-bit version of Sonic the Hedgehog 2. In the Zone, they are either seen floating in mid-air or are placed in between small pits full of spikes.

Sonic the Hedgehog CD
The fourth Round Quartz Quadrant in Sonic the Hedgehog CD features conveyor belts as main gimmicks, which are set everywhere, even in the ground and platforms. In Quartz Quadrant, there are small switches with arrows pointing the moving direction of belts, that can be changed by touching it. There are holes with conveyor belts on each side, which can be used to time travel after running past the Past or Future Time Warp Plate. If the player changes the belt movement in the tunnel by jumping on the switch, the player will keep jumping and going down the tunnel while gaining speed to transport in time.

In the boss encounter in Quartz Quadrant, Doctor Robotnik also uses a conveyor belt to trap Sonic while dropping bombs on him. Sonic has to keep running due to spikes to the left sideof the conveyor belt. The player has to survive on the arena long enough for Robotnik's cockpit to overload due to being set over the moving conveyor belt. Later in the game, Metallic Madness also features several suspended conveyor belts.

Sonic & Knuckles
In Sonic & Knuckles, conveyor belts are featured in Death Egg Zone, while there can be elevators with long, active conveyor belts, where the player has to balance Sonic's movements while avoiding holes that shoot tiny missiles toward him. These conveyor belts change direction at random, and can force the player into spikes on the walls if they are caught off guard. There are also smaller ones which don't have belts rotating onthem. Instead, the platform itself can move on rooms full of electric generators.

Sonic the Hedgehog Triple Trouble
Sonic the Hedgehog Triple Trouble is seen featuring conveyor belts in Tidal Plant Zone, where they are only set on to the ground like at Quartz Quadrant in Sonic CD. They are seen on both overworld and underwater sections of the Zone, and while moving on them, the player has to avoid small explosive bombs that fall down from small tubes to conveyor belts.

Tails Adventure
In Tails Adventure, conveyor belts are common gimmicks in Coco Island and Battle Fortress 2. Due Tails' and Remote Robot's medium speed, conveyor belts can be extremely tricky due the placement of enemies, Electric Generators or Spikes on certain points. In Battle Fortress 2, certain machines drop non-functional droids of the Battle Kukku Empire, that move along the conveyor belt (the player needs to avoid from getting damaged), fall out and got destroyed. In the same Stage, there are machines that can reverse the moving direction of conveyor belts. The player needs to have Wrench being equipped in order to reverse the moving direction.

Sonic 3D Blast
In Sonic 3D Blast, the boss encounter of Gene Gadget Zone takes place on a wide, moving conveyor belt, that moves against the player toward where set of spikes are located. The player has to avoid spike placements that come along with the belt from asmall, wide hatch. When Robotnik lands above the conveyor belt to shoot missiles from his Egg Mobile, the player gets chance to attack.

In the last Zone of the game, Panic Puppet Zone, there are slowly moving conveyor belts that transport Sonic to the other part of the Zone. Some conveyor belts go in the wrong direction, and have to be changed by pulling the switch to the other side.

Sonic Adventure
Conveyor Belts are also seen in one room of Final Egg in Sonic Adventure. They are extremely fast moving, and the player has to jump on them to get to the other side of the room or risk falling into a huge bottomless pit and avoiding large moving spike attachments above.

Sonic Pocket Adventure
Conveyor Belts are featured somewhat less in Sonic the Hedgehog Pocket Adventure. They are seen floating in mid-air in Cosmic Casino Zone and Gigantic Angel Zone. In both Zones, they work similarly like at Casino Night Zone and Metropolis Zone in Sonic the Hedgehog 2.

Sonic Advance
Conveyor belts in Sonic Advance are featured in three different zones: Secret Base Zone, Egg Rocket Zone and Cosmic Angel Zone. In all three Zones, conveyor belts are seen to have slightly different appearance each time. Secret Base Zone has rusty looking ones, Egg Rocket Zone belts are more bright, and Cosmic Angel Zone belts are more colorful from all three variations. The moving direction of conveyor belts in Cosmic Angel Zone is also easier to recognize, as belts are seen to have arrows pointing the direction.

Sonic Heroes
In Sonic Heroes, two extremely fast moving conveyor belts are featured at Egg Fleet, which are located on the inside hall of large battleships. As the conveyor belts move quickly in the opposite direction, the player should use speed formation and use Rocket Accel repeatedly to charge towards the end of the dark hall. Once there, the playable team is automatically seen destroying the battleship itself and moving to the next part of the stage.

Sonic Rivals
In Sonic Rivals, conveyor belts are featured in Death Yard Zone. The conveyor belts are mainly colored grey with yellow arrows indicating their direction.

Sonic the Hedgehog (2006)
In Sonic the Hedgehog (2006), Radical Train has conveyor belts on a wooden building. They come in sets of two and switch between going forwards and backwards. The pattern changes when the player progresses on the wooden building.

Sonic Unleashed
In the Xbox 360 and PlayStation 3 versions of Sonic Unleashed, Eggmanland features wide and long conveyor belts above bottomless pits. This conveyor belt goes against the player at high speed, and the player has to avoid lasers, among other obstacles that come down the conveyor belt, such as boxes with spikes and bombs.

In Wii and PlayStation 2 versions of the game, all conveyor belts have also appeared only in Eggmanland, except they are only featured in Werehog acts of the stage. Here, they are less wider and normal, yellow/blue and grey colored treadmills, that have arrows showing the moving direction of conveyor belt.

Sonic the Hedgehog 4: Episode I
Conveyor belts are featured at Mad Gear Zone in Sonic the Hedgehog 4: Episode I, where they are mostly set individually or in small groups floating on mid-air. These conveyor belts aren't fast moving, but usually have Badniks on the other side waiting the player. Unlike in previous games, the player is able to jump through conveyor belts from below.

Sonic Lost World
In the Wii U/PC version of Sonic Lost World, conveyor belts are only seen in the interior sections of Lava Mountain Zone 3, where they function similarly like in previous games. However, several Spiked Balls can be usually on the player's way, as they are passing on the belt to the direction where it takes.

Trivia

 * In the 8-bit version of Sonic the Hedgehog, when the player sees the first conveyor belt in Scrap Brain Zone Act 1, one of them is seen to have 1-Up monitor moving to the edge and falling to the bottomless pit. The player is able to pick the extra life from the monitor if he/she is fast enough.
 * In Simon Wai's prototype of Sonic the Hedgehog 2, Wood Zone originally was supposed to have wooden conveyor belts. In the prototype, they are shown to be active, but don't function normally at all.