Win the Silver The Hedgehog Boss battle as Sonic.
Last Episode
Complete Sonic's Episode, Silver's Episode, and Shadow's Episode.
Free mode
Get an "S" rank on all of Sonic's, Shadow's, and Silver's levels, Bosses, and town missions.
Free mode characters
Complete the indicated task to unlock the corresponding character in Free mode.
Amy Rose: Complete all Soleana mystery missions with an "S" rank.
Blaze the Cat: Complete all Soleana mystery missions.
E-123 Omega: Complete all GUN Commander missions with an "S" rank.
Knuckles the Echidna: Complete all Town Stage missions with an "S" rank.
Miles "Tails" Prower: Complete all Town Stage missions.
Rouge the Bat: Complete all GUN Commander missions.
Audio Room music
Complete the indicated episode with a 100% rank to unlock the corresponding theme in the Audio Room.
Elise's Theme: The Last Episode
Shadow's Theme (All Hail Shadow): Shadow's Episode
Silver's Theme (Dreams of An Absolution): Silver's Episode
Sonic's Theme (His World): Sonic's Episode
Extras menu
Successfully complete Sonic, Shadow, or Silver's Story mode 100% to unlock the "Extras" option at the main menu with "Audio Room" and "Theater Room" options.
Play as Shadow The Hedgehog
Successfully complete City Crisis as Sonic.
Defeating Silver
When you fight Silver as Sonic, first do a slide move into him as he is falling from the sky. Then, collect a ring and run around until you hear "How bout this?" and do a homing attack on him. Run away again until you hear "How bout this?" again and do another homing attack again. Repeat this until he has been defeated.
Defeating Solaris
First, use Silver to weaken him until his first arm guard falls off. Then, switch to Shadow and hit him with the beams until his second arm guard falls off. Next, use Sonic to defeat the rest of his first form. Then, just use all three to survive the blows of lasers, and continuously attack.
Mini Sonic
Select multi-player mode and choose Battle mode. Select Silver and Sonic and go to any level. Get to the first checkpoint and have Sonic fall and appear at the checkpoint. However, do not move him. Then, make Silver fall and appear at the checkpoint. Just when Silver appears, freeze Sonic. When he is frozen he appears very small.
Very fast Sonic
In multi-player mode in any level or match, equip the Red Gem on Sonic, Activate it and hold it, then die. While still holding the activation button, wait till you respawn. When you respawn, deactivate the gem. You will now run ten times faster than normal. Also, the time will automatically be slow
Cheats submited by James on Febuary 13, 2007