Due to the numbers being changed around in the English version, I think it'd be appropriate to say the numbers. In the same order; Business Card toy 5553282338 - Tunnel Endless game 5557325937 - Samurai Slice Endless game 5557268724 - Battle of the Bands 5557625688.
Hidden throughout the game are secret telephone codes. By entering them into the telephone in Rhythm Toys (requires 4 medals) you will hear secret songs/random sounds from the original GBA Rhythm Tengoku. Listed below are the telephone codes and where they are located: 831*831*831* - Business Card under Rhythm Toys (requires 1 medal) 2*21*98 - Tunnel Endless Game (requires 12 medals) 246936*1 - Samurai Endless Game (requires 17 medals) 44*82831* - Live Contest (must beat all 50 stages) Note:'*' denotes a musical note.
|Beat Bag||Get 19 Medals|
|Beat Machine||Get 14 Medals|
|Business Card||Get 1 Medal|
|Kappa DJ||Get 24 Medals|
|Octopus Machine||Get 11 Medals|
|Phone||Get 5 Medals|
|Slot Monster||Get 8 Medals|
|Coin Toss||Get 2 Medals|
|Glass Tappers||Get 22 Medals|
|Rhythmove Dungeon||Get 27 Medals|
|Samrai Slice||Get 17 Medals|
|Shoot-'Em-Up||Get 7 Medals|
|Tunnel||Get 12 Medals|
|Unlock All Songs||Perfect all 50 stages.|
|Basic Guitar Lessons||Beat Rocker (Stage 6-3) and have at least 15 medals.|
|Technical Guitar Lessons||Beat Rocker 2 (Stage 10-4) and have at least 35 medals|
Obtain a Medal on all 50 songs and there will no longer be any wait between Perfect challenges.
|Battle of the bands||Beat Remix 10|
|Airboard Minigame||Beat remixes 1 through 6|