A lightsaber, radar, spin effect (whatever you want to call it) contains concepts essential to learning canvas game development. This tutorial covers how to get objects moving along the outline of a circle with sine and cosine functions, and also covers the atan2 function which'll help you determine what angle something should be rotated to based on your mouse's positioning.

Just to be clear, I messed up the equation a little bit on the first whiteboard example. The coordinates 1 and 0 (1,0) are the results of sin and cos when an angle of zero is inputted. You should actually multiply the resultant value by your particle's distance from center, which'll produce the offset effect between particles (can't multiply Math.sin(1) by zero and get something other than zero like shown in the video).