Here's a shooting game that can sharpen your sense of speed. You can play this game with a friend.
It has three functions, the function to judge the player's speed, the function to judge the start signal, and the function to judge the foul signal.
Let's take a look at the schematic and see how to play this game. The two flip-flops judge the speed that determine which key is pressed first. If S1 is pressed first, LED 1 lights up. If S2 is pressed first, LED 2 lights up.
Turn on the switch. After a short period, LED 3 lights.
As soon as you see it lights, press S1 or S2. If a player press S1 or S2 before the LED 3 lights up, the LED display indicates the letter F (meaning "foul") and the speaker gives the foul sound. When this happens, release the key, turn power OFF, and then switch it ON again. The game re-starts.
You can adjust the time lag between power on to the start signal generation (LED 3 ON) by rotating the control volume.