Here are some cheats and tips for the game Revenge Of Shinobi.
Unlimited shurikens:
Select the “Shurikens” choice on the options screen
and set it to 00. After approximately ten seconds this value will
change to an infinity symbol.
End bonus:
Complete any level with a number of shurikens equal to 11
times the number of remaining lives. 30,000 bonus points will
be added to your score.