After you press the green flag, press the space bar to make the player go forward. PLAYER ONE (hippo) is controlled by the UP, LEFT, and RIGHT arrow keys. PLAYER TWO (horse) is controlled by the W, D, A, letter keys. Watch out for the baseballs, for they will place you back to the start. Collecting the diamonds will give you bonus points.
Thanks to Google CS First and everyone that just helped me see the fun in coding. :D