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 was built on a more advanced version of the engine used for "Sonic Heroes". It focused on Shadow the Hedgehog as he tried to uncover his past. The game contained multiple paths and endings, as the player chose to take good or evil paths for each level. It also added wielding weapons and driving vehicles to 3D platforming. "Sonic Riders" was the first "Sonic" racing game since "Sonic R"; in contrast to the previous game, the characters used hoverboards, bikes, and skates rather than racing on foot. It was the last game for GameCube & Xbox. Due to the extended