Sonic the Hedgehog 2 introduced the Spin Dash, a move charged while Sonic is standing still. By crouching and repeatedly pressing the jump button, players build up rotation before launching forward at high speed.
The Spin Dash solved a major design problem from the original Sonic. In the first game, Sonic generally needed a running start or a slope to reach top speed. The new move let players recover momentum immediately, attack enemies, break through obstacles, and climb slopes without needing a long approach.
It is easy to confuse the Spin Dash with the Drop Dash, which was introduced much later in Sonic Mania, or with the Boost mechanic associated with modern Sonic games. The Light Speed Dash is another separate ability, allowing Sonic to follow lines of rings in later titles.
The Spin Dash became one of Sonic’s signature actions because it combines speed, offense, and control in a single input. It also encouraged players to experiment with momentum, especially in the sequel’s larger and more varied stages.