All Shu generals
At the main menu, press White, Black, X, Y, White, R, L, Black. If you entered the code correctly, you will hear a sound.

Opening Edit option
At the main menu, press X, Black, Y, White, L, R, White(2). If you entered the code correctly, you will hear a sound.

BGM Test option
At the main menu, press L, White, Y, R, White, Black, X, Y. If you entered the code correctly, you will hear a sound.

Bonus FMV sequences
Enter the options screen from the main menu and select the "Opening Edit" option. Highlight the "Replay" selection, then hold L + R and press A. You will see all of the people from the gray army dancing. Additionally, highlight the "Replay" option at the "Opening Edit" screen, then hold Black + White and press A. You will see Zhu Rong singing.