Click the Green Flag to start. If not using a Makey Makey, see what the space, "a" and arrow keys do. To turn off the sound, press "s". For further info please visit this page: http://bit.ly/1wrjwlm To get the full benefit, attach a Makey Makey to a wired mannequin or similar device - even a paper drawing will suffice! Take a look at the Scratch code to see which body parts map to the keyboard.
Inspired by Josh Burker's Operation Game – http://makeymakey.com/guides/pdfs/MaKeyMaKeyScratchOperationGame.pdf Information on human anatomy from the Neurons Firing bog – http://neurons.wordpress.com/anatomy/