You can't tell if a J-K flip-flop is set or reset just by looking at it. This Project takes that simple fact and makes a game out of it.
As you can see from the schematic for this Project, you use SW-Rot to set or reset both J-K flip-flops. You can use this circuit as a game for two people.
One player takes select one of four position of SW-Rot.
Then one player presses the Key. If both players managed to "match," LED 1 lights. If not, a sound comes out of the Speaker.
Be sure to play with this circuit a few times and find out whether the LED lights when both flip-flops are set or reset (or both).
You can also use this circuit to "test" the compatibility of two people. If the LED lights, the two people are compatible; if you hear sound from the Speaker, then the people aren't compatible!
Try some variations of this basic circuit — see if you can add a multivibrator for example.