Go to the option screen where you can set your credit number, press
triangle+circle+square+X at the same time, you will get FREEPLAY.

Siu-kwong Yau


This only works on the Japanese version:

I found out that every times I hit the 
select button after I had died(at the count down)
it would always keep me with full credits for 
continues.

- Kumpol Trivisvavet