Each of your scenes requires a background image that defines how your scene should look. Add backgrounds to your game by adding PNG files to your project's assets/backgrounds folder.
Background PNGs must only contain the following four colors:
#071821,
#306850,
#86c06c and
#e0f8cf.
Colors that are not one of these hex codes will be matched to the nearest
color.
Backgrounds are divided into 8x8px tilesets so the total image size must be a multiple of 8px in both width and height. A background has a minimum size of 160x144px (the screen size) and currently a background can be no larger than 256x256px.
An image can contain no more than 192 unique 8x8px tiles at once due to memory limits. This means that even using the smallest background size possible you must repeat about half of your tiles. Where possible repeat tiles between images as they will be grouped together saving on total game size. It is recommended to use a tile map editor such as Tiled to ensure your backgrounds conform to the pixel grid.