Click the background to make noise! The circular thing is what I'll call a "Beat". Click the button with one Beat for one Beat, and click the one with Two Beats for two Beats. The closer the mouse is to the middle, the lower tone it makes. Click the palettes for different colors and sounds. The first palette is for the first Beat, and the second for the second Beat. The box that says 1 will make the first Beat follow the mouse, and the second Beat go the opposite way of the mouse. The box that says 2 will add controls, up and down arrow keys for the first, and w and s for the second. Pressing 1, 2, 3, 4, 5, 6, 7, of 8 will change the instrument of the second Beat. _DISCLAIMER_ The spaces don't indicate the different tones.
Full credit to Dinahmoe Labs to create the original. Here's the link: http://dinahmoelabs.com/_plink/ If it says you need camera, decline it. You don't need it.