Unlock Hidden Options: When you have inserted your coins hold Red + Blue + Start.
Unlock Faster flow: At the 'Song Selection' screen Press Green(3).
Change Flow Speed During Song: During gameplay hold 'Start' and press Blue to increase the flow speed and hold 'Start' and press Red to decrease flow speed. Repeating the coded to increase their effects.
Unlock Basic, Advanced and Extreme Modes: At the 'Song Selection' screen hold Green and press Pick(2). To cycle through the modes keep repeating the code.
Unlock Normal, Bass and Open Pick Modes: At the 'Song Selection' screen hold Pick and press Green(2), release Pick then press Pick again. To cycle through the modes keep repeating the code.
Disable Codes: At the 'Song Selection' screen Keep pressing Pick until the effects are disabled.
Unlock Extra/Encore Stage: On a Bonus or Standard track get an 'S' or better rank in every song.