Dynasty Warriors 3

Note: This game other title is Shin Sangoku Musou 2.

US Version Codes
At main menu screen, press:
All Charactera - R2 R2 R2 L1 Triangle L2 L2 L2 R1 Square
All free mode stages - R1 R2 L2 L1 Square L1 L2 R2 R1 triangle
All movies - Triangle L1 Triangle R1 Triangle Square L2 Square R2 Square
All Shu Characters - L1 Square Triangle R2 L1 L2 L2 R1 square L1
All Wei Characters - L2 L1 Square Triangle L1 L2 R1 R2 L1 L2
All Wu Characters - Triangle Triangle L1 square R1 R2 L1 L2 L2 L2
Opening item in options - R1 Square R1 Triangle R1 L1 Square L1 Triangle L1
Select Stages - R1 R2 L2 L1 Square L1 L2 R2 R1 Triangle
Sound tests - L1 L1 R1 R1 L2 L2 R2 R2 Square Triangle
Hidden endings - Highlight the "Replay" selection then hold L1 + L2 + R1 + R2
and press X.

Japanese version codes
At main menu screen press:
All 41 Characters - Square R1 Triangle L1 Triangle R2 Square L2
All Movies - L1 Triangle R1 Triangle L2 Square R2 Square
All Shu Generals - L1 Square Triangle R2 L1 L2 L2 R1
All Stages - R1 R2 L2 L1 Square R2 Triangle L1
All Wei Generals - Square Triangle L1 L2 R1 R2 L1 L2
All Wu Generals - Triangle L1 Square R1 R2 L1 L2 L2
Hidden endings - Hold L1 + R1 and press Circle
Opening Edit option - R1 Square L1 Square R2 Triangle L2 Triangle
Sound Tests - Square Triangle Triangle Square L1 R1 R2 L2