The game doesn't keep track of scores. I'm using a timer interrupt because it's best for my application. I don't want to have to keep track of time using millis() and have to continually subtract and check for elapsed time. It could be done, but a timer interrupt is ideal. I just have to figure out how to either do the assembly instruction "jmp 0" for the Arduino Due or a routine that causes the watchdog to time out and it would restart.