Does not have to have “holes”. The most front screen in the foreground can be where the main character and enemies dwell. The Upper part of the screen (clouds, parallax clouds etc) can be the screen behind because the front screen is halfway pulled down revealing the one behind, both syncronized and to the player they look as one. I really suggest Amiga coders look at Broadcast Titler on the Amiga and how it is achieving what it does.