The board game "Operation" is based on a very simple circuit, so you can build your own and customize it really easily!
Step 1: Intro and Materials
I first made this game when I was around 11 or 12, when I was on some rant about how the original Operation dude didn't wear any underpants. I told my mom she shouldn't let my younger brother play the game because it was inappropriate (I didn't actually believe this, though, I just liked arguing about things back then). So...I made my own (with boxers drawn on) and called it "Disease Remover". it's a very simple game to make, and it would make a really funny gift or practice for people who want to learn more about electronics.
Wire and wire strippers
2 AA Batteries and a holder
A small bit of spare cardboard