Main mechanic of my game is switching between two robots by throwing a battery from one to another. In the first level you play volleyball to get familiar with controls, but the ball you toss is actually a battery but with a different sprite and physics properties! Even in hierarchy it's called "Battery", because my cheeky GameManager needs to find it by name with a string :v
If you want to play it, there is some important info in the install instructions :)
https://huscat.itch.io/powerbros