You always go to your mouse. You get points by touching the Golden Snitch and lose points by touching the maroon circle with the yellow stripe. When asked how many points you want to make it to win, the answer must be a number. If you don't want a win condition, answer "infinity". The highest score I would put to win is 100, then it starts getting long.
I changed a bunch of things, to see all of them look at the original project. Thanks to m-et-j, the owner of the original project. Please give any constructive criticism. I have adjusted the game so it is beatable.