I once designed a custom PCB that fits inside the original NES four score case. You can connect 4 NES controllers to it and the inputs were sent to a Raspberry

I once designed a custom PCB that fits inside the original NES four score case. You can connect 4 NES controllers to it and the inputs were sent to a Raspberry Pi via UDP (so no wire between couch table and TV was needed). I think my PCB had more parts for its simple power supply than all 4 NES controllers combined. These things are an absolute masterpiece of simplicity!