Winding Tunnel

Twisting Tunnels, also referred as tunnels, are tight, fast-paced passageways and one of many gameplay elements in Sonic the Hedgehog games. They are usually formed through the level structure or underground sections. When the playable character enters the tunnel, he/she turns into Spin Attack mode and curls down the twisting tunnel, while gaining the high speed at the same time. Most of the time, they are somewhat automated sections in the game.

Despriction
Twisting tunnels are seen as part of the level structures, that have different formations in each game. While some of tunnels can be sometimes very linear, but usually creates winding routes, such as "Ƨ" formations. After the player enters the tunnel, he/she has less control and the playable character gains more speed afrer spinning out the tunnel. While not usually being able to, if the player is able to gain enough momentum, he/she is able to backtrack on twisting tunnels as well. If the player does not have enough of speed, the playable character normally rolls back to aperture.

Tunnels first appeared in Green Hill Zone in original 16-bit version of Sonic the Hedgehog. Tunnels usually go through tall level structures in the "Ƨ" formation. This is later repeated in Sonic the Hedgehog 2, where similar "Ƨ" shaped tunnel routes are featured in Hill Top Zone. Casino Night Zone has more different, automated tunnels, that are set between sections of Pinball Shooter and Shuttle Loop/pinball arena.

Sonic the Hedgehog CD contains many Rounds, where twisting tunnels are featured. They are extremely useful to gain enough of speed for the time travel. In Palmtree Panic, they are featured along with several ones, that can even converted into shuttle loop at the underground in the good and bad future versions of the Zone. When the player usually spins out tunnels, hatches close the aperture. Linear tunnel pathways are featured on Collision Chaos. "Ƨ" formed tunnels are also featured at Quartz Quadrant, while several linear tunnels contain conveyor belt systems to transport the player either up or down. Many tunnel sections are also featured at Wacky Workbench and Stardust Speedway.

Angel Island Zone Act 2 in Sonic the Hedgehog 3 features long and winding tunnel sections, that are blocked by breakable pile of rocks. Hydrocity Zone Act 1 features limited amount of linear tunnel parts most of the time below shuttle loops. IceCap Zone Act 2 contains tunnel sections, which are similar to ones from Hill Top Zone. At Flying Battery Zone in Sonic & Knuckles, when the player enters the linear tunnel part from below, the player normally doesn't turn into curling mode, but gets bounced by Springs inside the tunnel to reach to the end of it.

At Neo South Island Zone Act 2 in Sonic the Hedgehog Pocket Adventure, only two tunnel sections are seen, while more linear tunnel sections are featured at Cosmic Casino Zone. 3D variation of Green Hill in Sonic Adventure 2 features tunnel sections, which are heavily automated. In Sonic Advance, "Ƨ" formated tunnels are featured at Angel Island Zone. In Sonic Advance 2, some regular twisting tunnels are featured at Hot Crater and Ice Paradise, while Music Plant featured ones that loosely looked like French horns. In Sonic the Hedgehog 4: Episode I, "Ƨ" shaped tunnel routes oddly contain Dash Panels inside to give extra amount of speed. Tunnel sections are also seen in Green Hill of Sonic Generations.