Writing with python a small is not very complicated. The existing pygame library allows even newbies in doing so. Most tutorials are assuming that the game is created with the object oriented paradigm That means there are classes for the GUI, for the physics and for the main program. This assumption makes sense because since the advent of the C++ and C# language nearly all games are created this way.
A seldom mentioned technique for creating larger software programs was invented before tor the advent of C++. What was used before is called modular programming and can be realized with python as well. The interesting situation is that modular programs allows similar to OOP to divide a larger project into chunks which are created individual. First thing to do is to create the physics module which contains of a single file.
The formatting has similarity to a class but the class statement is missing. The next step is to create the main module which has also no classes but a variable for drawing the window and two methods. The interesting situation is that the physics module is not initiated as an object but it was only importad and then the main module is sending messages to it.
The game itself consists of a small circle on the screen which can be moved with cursor arrows left and right.
