The game has been referred to by a number of different aliases, including Sonic 2006, Sonic '06, Sonic: 15th Anniversary, Sonic 360 and Sonic Next-Gen. Most of these nicknames were coined by the Sonic fandom.
The game faced development issues which resulted the product being rushed and ultimately a poor product being delivered. Upon release, it was widely criticized for its numerous gameplay glitches, long loading times and complicated plot.
Although each character plays the same levels, each character's unique abilities allow him or her to get to different areas of each stage, and deny them from accessing certain items. Levels are far less linear than previous 3D Sonic titles, offering up many alternate pathways through each stage. Certain areas in each of the levels, dubbed "Mach Speed Sections", allow Sonic to reach speeds that would be unattainable elsewhere, though at the cost of always moving forwards without being able to stop.
Gameplay is broken up into two gameplay styles, similar to Sonic Adventure: Action Stage and Town Stage. Action Stages are primarily where the bulk of the gameplay takes place, whereas Town Stages are free-roaming locations where the player can talk to non-player characters and explore, similar to Sonic Adventure's Adventure Fields.
For each of the action stages in the respective stories, gold medals are obtainable by achieving S rank in these stages or completing it (Both in Normal and Hard mode), or by obtaining all 10 Silver Medals on the stage, giving a total of 5 Gold Medals per stage.
The ranking system in the game for each of the levels and the town missions is similar to Sonic Rush, providing score ranks with the highest rank being S while the lowest rank is D, unlike previous Sonic games where the lowest was E and the highest was A.
- Sonic the Hedgehog
- Shadow the Hedgehog
- Silver the Hedgehog
- Miles "Tails" Prower
- Knuckles the Echidna
- Amy Rose
- Rouge the Bat
- E-123 Omega
- Blaze the Cat
- Princess Elise the Third
- Duke of Soleanna
- Dr. Eggman
- Mephiles the Dark
Action Stages Edit
- Wave Ocean
- Dusty Desert
- White Acropolis
- Crisis City
- Flame Core
- Radical Train
- Tropical Jungle
- Kingdom Valley
- Aquatic Base
- End of the World
Unused Voices Edit
Voice Reel DemosEdit
Voice Cast Edit
- Jason Griffith as Sonic the Hedgehog and Shadow the Hedgehog
- Amy Palant as Miles "Tails" Prower
- Dan Green as Knuckles the Echidna and Mephiles the Dark
- Lisa Ortiz as Amy Rose
- Kathleen Delaney as Rouge the Bat
- Maddie Blaustein as E-123 Omega
- Bella Hudson as Blaze the Cat
- Pete Capella as Silver the Hedgehog
- Lacey Chabert as Princess Elise the Third
- David Willis as Duke of Soleanna
- Mike Pollock as Dr. Eggman