A classic game of logic.  Turn all the lights out in as few moves as possible.  Uses somewhat 'real' looking buttons that push in and pop out.

The classic 2-player game of Checkers.  Uses Drag and Drop style of mouse input for moving the checkers.

This is cool, TomDad, thanks!  What's most amazing is you did this in about 50 instructions - cool! As Hymake said, it's very hard, because it goes so fast.  I added a 100 millisecond delay to the main loop, as shown here - that's only 1/10 of a second - and now I can actually play it, slow oldish guy that I am, lol!  ...