Double Dragon Advance (GBA)
CheatingDome.com
10 credits
In the options prompt, hold Select and push L, R, Down, L, R, Down, L, R, Right.
Background music selection
In the options prompt, hold Select and push R, L, R, L.
Expert mode
In the options prompt, hold Select and push Up(2), Down(2), Left, Right, Left, Right.