Unlock the following bonuses by performing the corresponding tasks:
BONUS - HOW TO UNLOCK
Last Episode - Complete Sonic's episode, shadow's episode, and silver's episode.
Play as Shadow the Hedgehog - Complete 'crisis city' with sonic.
Play as Silver the Hedgehog - Complete 'silver the hedgehog' boss battle with sonic.
Theater and Audio Room - Complete sonic, shadow, or silver's story 100%.
Unlock Free mode:
To unlock Free mode, get an "S" rank on all of Sonic, Shadow, and Silver's levels, bosses, and town missions.
Unlockable Free Mode Characters:
Unlock the following Free mode characters by performing the corresponding tasks:
CHARACTER - HOW TO UNLOCK
Amy Rose - Complete all soleanna mystery missions with an "S" rank.
Blaze the Cat - Complete all soleanna 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.
Unlockable Audio Room music:
Unlock the listed theme song in the Audio Room by completing the corresponding episodes with a 100% rank:
THEME SONG - HOW TO UNLOCK
Elise's Theme - Complete "the last episode".
Shadow's Theme (All Hail Shadow) - Complete "shadow's episode".
Silver's Theme (Dreams of An Absolution) - Complete "silver's episode".
Sonic's Theme (His World) - Complete "sonic's episode".
Get shoes from shoemaker:
After the the video clip of the Princess of Soleanna, go through the town square towards the store, and you will see an old man with a mark on his head. Talk to him so that you can test out some new shoes he just made. He will let you keep them.
In multi-player mode with Sonic, equip the red gem. Activate it and then die while continuing to hold the activation button until you respawn. After you respawn, deactivate it. You will now run a lot faster and time will slow down.
The following gems have the corresponding functions:
GEM - FUNCTION
Dark Blue - Speed.
Red - Slow down time.
Green - Make a tornado.
Purple - Shrink yourself and multi-jump.
Light Blue - Mega jump.
White - Control the direction of your homing attack.
Yellow - Attract rings.
Unlock Extras menu:
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.
When fighting 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?" Do a homing attack on him when you hear it. Run away again until you hear "How bout this?" again and do another homing attack again. Repeat this until he is defeated.
First, use Silver to hurt 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. Finally, simply use all three to survive the blows of lasers while continuously attacking.
Big enemies strategy:
When facing an enemy that requires more than one hit, use your Homing Attack on it and follow it up with a Bounce Attack. Note: You must first have the Bounce Bracelet.
Mini Sonic hints:
On multiplayer mode, select Battle mode. Choose 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. He appears very small when he is frozen.
Blaze in barrel hint:
Choose Sliver from the Episode selection menu. Note: This works best if you have completed Sliver's mode. Move to the part of the pier from where as Tails or Sonic you travel to Wave Ocean. Next to the building is a barrel with no cover. If desired, go inside. This makes it easier to get Blaze in. After a couple attempts of spinning in circles, Blaze should come in. If you are near the edge of the barrel, use Psychokinesis to see Silver's head pop out of the barrel. If you have plenty of patience, you can get Blaze to be in the barrel and Sliver on top after fooling around with it.
Farther jumps with Silver:
Jump with Silver by pressing X, then pressing the same button again while in mid-air. This makes Silver float around. When floating in mid-air, tap X while moving in any direction instead of holding the button down. This will make Silver jump a longer distance.
Sideways jump glitch:
Choose Sonic from the Episode selection menu. Note: this works best if you have completed Sonic's part. Go to the building that is part of the Desert Stage (not the place where the Transportation Mirror is located). On the opposite side of the mirror, there is a wall. Use the "Sliding" technique to get under the wall. While Sonic is landing on the roof, Sonic should do a sideways spin instead of a normal one. Note: This may not work every time.
Infinite jump glitch:
There is a glitch in the purple gem you can buy at the market. The purple gem lets you to "change size" in the description, shrinking you down to fit in small areas. However, when using the gem for Sonic, you are able to jump infinitely. When you press Jump while holding Activate Gem and repeatedly tap A, your character will act as if he wants to do the homing attack. However, the game glitches, cancels it out, and lets you to jump as many times as desired while moving in the direction you wish to go. This lets you reach interesting parts of Soleena or an action stage that you were not meant to access. If you die or find a alternate way to lose the gem, it will be "out of stock" for some time.
Float into the air glitch:
In Soleona, go on top of a metal box in the military base portion of the map. Stand on top and repeatedly tap SQUARE. If done correctly, you will start going into the air. The longer you tap SQUARE, the higher you will go.
Exiting boundaries when fighting Silver:
As Sonic in Story or Trial mode, choose the Silver Boss battle. Get as many rings as possible (fifteen), then go to the alley in the corner. Get as far into the corner as possible. When Silver uses his levitation technique, try to get back in the corner. Silver will use the levitation technique again and the rings will be behind you. You should be able to collect the rings before hitting the wall and dieing. Then, when you hit the wall, try collecting your rings. You will then go outside the level's boundary. You will be able to walk on invisible bridges and hit other invisible things. Silver might even also get out of the level boundary and throw you out of Soleona, causing you to keep flying forever.
Very high in the air glitch:
At the checkpoint just before meeting the whale, you should be on a mountain. Jump and turn around when you are past the checkpoint and use the Sky Gem. Turn the camera until you can see Sonic directly, then release R1. If done correctly, Sonic will go very high and he should be in "space" or a black screen with only the sun showing.
Use Silvers telekinesis when facing Shadow to pick up items and knock him down with them. If you try picking up Shadow, he'll hit you when you try and throw him. Using this strategy will eventually wear Shadow down.
Centurion - Get 100 or more rings.
Clear Green - Clear the Green Hill Zone.
Fast Green - Complete Green Hill Zome Act 1 in under 35 seconds.
Fast Marble - Complete Marble Zone Act 1 in under 80 seconds.
Star Light Zone - Get to the Star Light Zone.
Spring Yard Zone - Get to the Spring Yard Zone.
Labyrinth Zone - Get to the Labyrinth Zone.
Chaos Emerald - Get one Chaos Emerald.
Chaos Master - Get all the Chaos Emeralds.
Win - Complete the game.
Fast Win - Complete the game in under 40 minutes.
Perfect Win - Complete the game without dying.