Am I writing use cases correctly?

I’m a college student and I’m working with someone on a video game. She asked me to write use cases for the project. This is my first time writing them, so I read about it online. I drafted a few basic ones but I’m not sure if I’m doing it correctly. I want to learn how to do them correctly before I go further.

Are these good use cases? Am I misunderstanding what use cases are?

New players can create a new game file

Existing players can continue their existing file

Players can save their progress in their file

Players can exit the game

Players can pause the game

Players can earn money

Players can spend money in-game

The game will check if the player has enough money

If yes, the player will spend the money and obtain something in return If no, the game will cancel the transaction