Everyone seemed to have a pretty good time last week, but this time let's try something in the more formal CSCI l201 style.
Design a sprite so that when you click on it, it will disappear ("hide") for a short period of time. To make it a bit more fun, try making a sound (easy) and perhaps even changing the background (hard) when the sprite is clicked.
Add a variable to your sprite, so that after it is clicked a certain number of times it has a new costume.
Put your sprite in "forever" loop and have it move around. The idea is to make it harder to click. You might try having it sweep across the screen quickly or just move in seemingly random ways.
Make a copy (or two) of your sprite, so that there are multiple sprites to hit.
I think this one would be hard, but make the sprite avoid the computer mouse. For example, if the computer mouse was within 60 units of the sprite, the sprite could just to a different corner of the screen.