Spy Hunter 2 All missions and weapons
At the main menu, press L, Black, White, R(2), White, Black, L to unlock all missions and weapons.
Invincibility
Pause the game and press L(3), Black, L, R(2), L, Black. Repeat the code again to disable it.
Infinite ammunition
Pause the game and press R, L, Black(2), White, R, L, Black, White. Repeat the code again to disable it.
The image featured at the top of this post is ©The Legend of Heroes: Trails of Cold Steel III key art / Original