JavaScript

Hi I have this Javascript thing here http://jsbin.com/AGeCELE/1/edit

That I want the larger block to be positioned at the coordinates at the bottom center canvas.

I also want to enable on a keystoke such as the space bar is hit enable the bigger block to attack the little blocks

If somebody to guide me through how to do this that would be great.

I have not got much knowledge of JavaScript. As you can probably tell.

If you could help that would be great.

Thanks