input these at the main screen

Unlock all free mode stages- R1 R2 L2 L1 Square L1 L2 R2 R1 triangle

Unlock all movies in gallery- Triangle L1 Triangle R1 Triangle Square L2 Square R2 Square

Unlock "Opening" item in options- R1 Square R1 Triangle R1 L1 Square L1 Triangle L1

Unlock all sound test BGMs- L1 L1 R1 R1 L2 L2 R2 R2 Square Triangle

Unlock all Shu Chars- L1 Square Triangle R2 L1 L2 L2 R1 square L1

Unlock all Wu Chars- Triangle Triangle L1 square R1 R2 L1 L2 L2 L2

Unlock all Wei Chars- L2 L1 Square Triangle L1 L2 R1 R2 L1 L2

Unlock all Chars- R2 R2 R2 L1 Triangle L2 L2 L2 R1 Square

input these at the main screen

All movies:
At the title screen, press L1, Triangle, R1, Triangle, L2,
Square, R2, Square

All characters: 
At the title screen, press Square, R1, Triangle, L1, Triangle,
R2, Square, L2

All Shu generals: 
At the title screen, press L1, Square, Triangle, R2, L1, L2, L2, R1

All Wei generals: 
At the title screen, press Square, Triangle, L1, L2, R1, R2, L1, L2

All Wu generals: 
At the title screen, press Triangle, L1, Square, R1, R2, L1, L2, L2

BGM Test option: 
At the title screen, press Square, Triangle, Triangle, Square,
L1, R1, R2, L2

Opening Edit option: 
At the title screen, press R1, Square, L1, Square, R2, Triangle,
L2, Triangle

Free mode all levels: 
At the title screen, press R1, R2, L2, L1, Square, R2, Triangle, L1