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 4: Episode II going, so I'd hope to provide Episode 2 then." He also said that Sonic Team "knew about the anniversary year," and that ""Generations" was planned way in advance." As such, "it was always our plan to release Episode 2 after Generations." In preparation for "Episode II"s release, Sega re-released "Sonic the Hedgehog CD" to digital platforms in late 2011, billing it as a 'prequel' to "Sonic 4", as the events of "Episode II" would rely heavily on what occurred in "CD". On December 29, a teaser trailer for "Episode II" was released, and it was revealed that both Metal Sonic