Take the money, cat!

Let’s assume that there is a cat (a girl but it’s a smart contract) on the ethereum blockchain.
You want to give a tip to her for being together always while you are coding. ???
But she doesn’t understand your word.
How will you force her to have that money (ETH)?

In ethereum world, not only stealing someone else’s money but also giving money to others is not possible always.

I made a Solidity game you can play with.
Through it, you can learn about a special way to send ETH to a contract, even if the receiving contract has no payable function.

Ready?
Let’s go: https://github.com/maAPPsDEV/force-attack