Somersault

The Somersault (サマーソルト), also known as Somersaulting, is a technique introduced in Sonic Adventure 2 and is used exclusively by Sonic the Hedgehog, Shadow the Hedgehog, Amy Rose, and Metal Sonic. Basically, the move involves the user attacking, while performing a somersault. It has since then appeared on Sonic Adventure 2: Battle, Sonic Advance, and Sonic Lost World.

Description
While standing still or moving at high speed, by pressing the action button, the user can perform the Somersault by flipping his/her body, and then proceed to attack with his/her legs. Once colliding, all enemies or weaker obstacles are destroyed. In Sonic Adventure 2, this move can be upgraded with the Flame Ring, becoming the Fire Somersault.

Sonic Adventure 2
The Somersault first appearance was in Sonic Adventure 2 and is only usable by Sonic, Shadow, Amy and Metal Sonic and is an ideal move for close combat. If timed correctly, the Somersault can be used in combo attacks. It is, however, not as fast as the Spin Dash.

Beside offensive maneuvers, the Somersault can also be used to slide underneath hazards, into small openings in walls, climb steep hills and so forth. If Sonic and Shadow receives the upgrade Flame Ring, they can perform a stronger version of the Somersault called the Fire Somersault.

The Somersault move would later appear in the Sonic Adventure 2 remake, Sonic Adventure 2: Battle.

Sonic Advance
In Sonic Advance the Somersault comes in three steps, if pressing the B button at the right time, and is only used by Sonic. While moving forward and pressing the B button, Sonic goes into a grounded Spin Attack, which can still damage obstacles. Pressing the B button a second time while in the roll, makes Sonic perform a normal somersault, and pressing the B button a third time makes Sonic perform the Skid Attack. However, if pressing the A button while in the somersault, it makes Sonic do a back flip.

Sonic Lost World
The Somersault move reappears on Sonic Lost World as one of the reinvented moves Sonic can use thanks to the Parkour system. With this move, Sonic can jump while at high speeds to perform a Somersault. On the Wii U version, Sonic must run at a fast pace and jump quickly to perform a Somersault. For the Nintendo 3DS version, however, Sonic must run at his fastest pace, as well, but the Kick ability has been added for when Sonic is performing a Somersault, he can hit badniks or other enemies with the Somersault Kick attack. The Somersault Kick attack is one of the other things like the Somersault that was reinvented by the Parkour system.