I think I was in my 30s before I found out that with NES Duck Hunt, if you plugged in a controller, player 2 could control the duck.
If you want to try it out just run Duck Hunt on an emulator. You dont need a crt to just play with the duck
The game manual says that you can control the duck with the control pad (which is in player 1's controller port), which would usually be controlled by a second player. This isn't a secret to anyone who bothered to read the manual.
https://www.gamesdatabase.org/Media/SYSTEM/Nintendo_NES/manu...
/s
The highest purpose of this feature is to surreptitiously control the ducks while someone who doesn’t know about the feature is playing. You’ll have them cursing in no time :-)