Use your Arrow Keys to move up and down. Press the Space Bar to shoot. There is a Glitch where after playing for the first time, in the second level there is no Apple shooting. To fix this, you must go inside, change the backdrop to the first backdrop, click save now (unless it already saved), then refresh the page, and then it should work. Also, you should do this if it shows up as the won screen, or if it has the level 2 backdrop (strange planet).
Thanks to my Teacher to give me the idea to make this. It took me a few hours of hard, concentrating work. On, second thought it took a few weeks of very loose concentrating during my Engineering class. It is every other day, so give me a break. I have had this class about 10 times, Which equates to approximately 10 hours. HOPE YOU SOMEWHAT ENJOY!