Secrets
Unlock the "extra" stage/difficulty
To play the extra stage in challenge mode you must get EXACTLY 125
''Challenge'' points by your final song. It MUST be on 9 key and equal 125
by your final song. If you did this correctly, you should be able to play
another stage, it will have the same difficulty bar as in expert mode, and
you can now select the ''EX'' difficulty on certain songs.

PS2 Cheats for Pop'n Music 7

Pop'n Music 7 cheat codes

Pop'n Music 7 cheats