Sega Classics Arcade Collection

Choose arcade mode, then press Down/Left + B + Start. A number will appear in the top left part of the screen. Press Up or Down to select the starting level.

Select the shuriken number at the options screen and set the number of shurikens to zero. The zeroes will eventually turn to an infinity symbol to confirm correct code entry.

Choose arcade mode and push Down/Left on the control pad. The characters will start rotating, then push B and Start simultaneously to display a stage number in the upper left corner of your screen. Push Up/Down to choose a level number

Select the Options selection in the title screen. After that, hold simultaneously Right, A, B and C on controller number two. Then, push start on controller number one.

Select "Options" at the main menu, then hold Right + A + B + C on controller two and press Start on controller one.

Go to the options menu and switch your number of shurikens to zero. Remain highlighted on the shuriken option for over 30 seconds and the zero icon should be replaced by an infinity symbol. You now have an unlimited supply of shurikens.