Sonic the Hedgehog platforming of the main levels. The 16-bit "Sonic the Hedgehog " consisted of a giant rotating maze, which many considered a major technical achievement. The most common special stages, however, were segments with the character running through a long tunnel to collect certain items. 3D "collect item" levels, as in "Sonic 3" and "Sonic & Knuckles", used the same perspective but had Sonic collecting all the blue-colored orbs on the surface of a giant sphere. Finally, "Sonic Advance 2" employed a 3D ring-collecting stage, and "Sonic Chaos" ("Sonic and Tails" in Japan) used a variety of gimmicks for its levels.
Sonic the Hedgehog speed, near-invincibility and a change in color. In some games, characters are still vulnerable to being crushed, drowning, falling into a pit or running out of time. Depending on the type of transformation, the condition to attain such a form is an individual making contact with all of the Chaos Emeralds, the Sol Emeralds, or the Master Emerald. Super transformations first appeared in "Sonic the Hedgehog 2", where Sonic transforms into Super Sonic if all seven Chaos Emeralds and fifty or more rings are held at the same time. While in Super Sonic form, Sonic gains invincibility (except from instant-kill