Dance Dance Revolution 2nd Mix cheats and cheat codes for Dreamcast

All songs:
Go to the title screen, then choose ARCADE MODE. At the Play Mode 
selection screen highlight "HARD" and press RIGHT on the D-Pad 
3 times and start a game.

Character and Arrow Select:
Go to the title screen, then choose ARCADE MODE. At the Play Mode 
selection screen press the analog pad in any direction to bring up 
the character select and arrow select screen.

Unlock Little, Mirror and Hidden Modes:
Go to the title screen choose ARCADE MODE. Select any play mode (easy,
normal or hard). Now at the song selection press the analog pad in
any direction then do the following to unlock the different play modes:

Unlock "Hidden mode":
Press Up, Down, Up, Down, Up, Down, Up, Down.

Unlock "Mirror mode":
Press Left, Right, Left, Right, Left, Right, Left, Right.

Unlock "Little mode":
Press Left, Down, Right, Down, Left, Down, Right, Down, Up.

Unlock Single Play, Couple, VS and Double game options:
Hold B while choosing the arcade mode at the title screen