Game Not Running On Full Screen

Hi All,
I bought Samsung Galaxy S8 today and the game which I installed first was Bakery Story but I noticed that this game is not running in full screen. Why is it so?
Please help. There must be a Samsung Galaxy S8 user here. Please tell me how you are using this game in full screen.

Checking on this.

I am sorry but Android 8.0 OS has compatibility issues with the games. Sorry