You can return to the home screen anytime. While playing on TV, open the Settings and select “Quit to Title.” You can access settings by pressing Esc while playing with a keyboard and mouse or, if you’re playing with a controller, tapping the ☰ (Settings) button on your controller.
If playing Underwatermelon: Fruit Merge on your mobile, look for the cogwheel (⚙) icon in the upper right corner of the screen and press the Home Screen button.