Super Fast Sonic
Buy the Red Gem and equip Sonic with it at any point in multiplayer mode. Activate the Red Gem, hold it, then die, but continue holding the activation button. Wait until Sonic respawns and deactivate the gem. Sonic will run much faster and time will automatically slow.
Free Mode
Achieve an ̶0;S̶1; rank for all Sonic, Silver and Shadow levels, all town missions and bosses to get to free mode, where you are allowed free access to all levels and all missions. Getting an "S" rank is achieved by accomplishing different things in different battles and missions. Sometimes you have to kill as many enemies as possible in the shortest amount of time. In the "Test of Intelligence," you must quickly choose the right portals and avoid the spring at the end.
Free Mode Characters
In free mode, you can unlock several new characters. With an ̶0;S̶1; rank, pass all Soleana missions to get Amy Rose. Blaze the Cat is unlocked by passing all of the Soleana missions. E-123 Omega can be unlocked with an ̶0;S̶1; rank and passing all GUN Commander missions. Pass all GUN Commander missions to get Rouge the Bat. With an ̶0;S̶1; rank, pass all Town Stage missions for Knuckles the Echidna and
Miles ̶0;Tails̶1; Prower.
Silver the Hedgehog
To play as Silver, Sonic must win the Silver the Hedgehog boss battle. Once you defeat him, you̵7;ll unlock his episode. To defeat Silver, do a slide move into Silver when he falls from the sky. Collect a ring and run around. Once you hear ̶0;How 'bout this?̶1; do a homing attack on Silver, then run around again. You̵7;ll hear ̶0;How 'bout this?̶1; again, so do another homing attack. Continue doing this until you have defeated Silver.
Shadow the Hedgehog
Unlock Shadow̵7;s episode by successfully completing Crisis City with Sonic.
Extended Jumps with Silver
Jump with Silver while simultaneously pressing X. While in mid-air, press X again to make Silver float. While Silver is floating, tap the X when he's moving in any direction to make him jump farther.
Defeat Solaris
Weaken Solaris with Silver. Once his first armed guard falls, switch to Shadow and attack with the beams. When the second armed guard falls, use Sonic to beat the rest of his first form, then survive the blow of lasers by using all three and continue attacking until Solaris is defeated.
Big Enemies
To defeat any enemy that needs more than one hit, get the bounce bracelet, which is in the pyramid cave. Once you have the bracelet, you can use the homing attack on your enemy and then the bounce attack.
Last Episode
Once you have successfully completed Sonic, Silver and Shadow̵7;s episodes, the last episode will be unlocked.