There's a scene in "That 70's Show" where Kelso and Red bond over Pong and decide to mod the game to make it harder. And a few hours later with a soldering iron, smaller paddles!

The first time I saw that episode was at a friend's house. I felt so smart telling him that was impossible because you can't mod software with a soldering iron. Then his dad poked his head out from the kitchen and told me Pong didn't have software.

Turns out the only impossible part of that episode is the idea of it taking a few hours. Changing the paddle size was a mod already supported by the hardware and the manual gave details on how to do it. Though it wasn't necessarily intended as a difficulty setting, it was intended to support different sizes of TVs. iirc, all you need to do is solder 1 jumper.