Sonic Rush Adventure Codes -

Play as Blaze:
Defeat the Kraken Boss in World 3 (Coral Cave) to play as Blaze the cat.

Sound test:
Defeat the Titan Boss in Big Swell. Then go to Seagull Beach on Windmill Island. Talk to the koala with the guitar to hear the music, dialogue, and sound effects. Note: This will also open additional missions.

Bonus level:
Collect all Sol Emeralds and Chaos Emeralds to unlock the "Deep Core" extra final Boss level.