Good Concept, Bad Game
This was a good idea. I agree with the opinion that the cursor should center on that ball. That would make the game much easier to control.
Also, there are so many great directions you can take this beyond a ball and a platform. I'd really like to see you express your creativity in this, and make a simple game into something with a little more meaning.
Up the graphics and dream up a plot and you could have a really good game on your hands. :)