K-1: The Arena Fighters cheats and cheat codes for Playstation

Unlimited energy for both players:
When "Push Start" begins to flash on the title screen, quickly press
Up, Right, Down, Left, Up, Right, Down, Left, Select on your controller. 
A sound of an explosion will confirm the correct code entry.

Play as Master Ishii
Choose the team battle mode, then press Up, Up, Down, Down, Left, Right, 
Left, Right, Start at the character select screen. Master Ishii will be 
selectable.

Watch the ending movie
Hold L1 + L2 + Triangle + Circle + Left on both controllers and the 
power button on your PSX. Keep held all buttons until demo mode 
starts to watch the ending movie and credits.

Change costumes
Hold L1 + R1 at the title screen. If the code is accepted, you will 
hear 3 beeping sounds. Now push the Start button to select different 
character costumes for Andy Hug, Musashi and Sam Greco.

Set strength level
Pause the game play and press L2, R1, L1, R1, L2, R1, then change the 
flashing numbers on either side of the screen to any value 
between 1 - 9 by using the D-pad on either controller.