The Golf Putter – has been a project which has been a particular favourite of students over the years – this particular variant uses the seven segment display circuit shown here - https://sites.google.com/sheffield.ac.uk/diamond-electronics/3-building-and-testing-circuits/7-segment-display . A PCB was designed and produced by the student and is triggered by a microswitch, activated when the golf ball falls into the hole counting up one each time! I have built many counting type games using this circuit.