Conan Infinite energy
At the title screen, press Up(2), Left, Down, Left, Right.
Power-up attacks
At the title screen, press Left(3), Up, Down, Right, Left.
Faster running
At the title screen, press Left, Right, Up, Down(2), Right.
Alternate costumes
At the title screen, press Left, Right(2), Up, Down, Left.
The image featured at the top of this post is ©Square Enix.