Games will shrink and adjust to a lower resolution in accordance with the aspect ratio. For example, a game with a resolution of 400x800, we make it smaller:
Setting “Change width to fit the screen ow window size”:
That is, the height will be fixed, and the game will be cropped in width.
Try experimenting with the settings and resizing the screen, you will see the result. Also, the size of the game window can be changed through the code. Write the code in which you will change the size of the game window (to whatever you need) and see the result. Practical experimentation will help you figure out the possibilities faster. =)