Left and right arrows to move the ninja, up arrow to jump, and space to throw the shurikens. P.S. You may have to throw a few shurikens to kill the bad guy.
My high score is 635 Thanks to WillWam for the sprites, and the idea. What used to happen was that when you run out of shurikens, your high score - whatever your score is - will become your score even if it is lower. I fixed this on 5/17/18. Enjoy! Here is The Shuriken: Unlimited, which I made on my other account. https://scratch.mit.edu/projects/214609278/