The woods Backdrop keeps the moon in a fixed position. The 2 moving sprite in the background are vectors, with the 'darkness' removed to expose the moon. Trees are 'rearranged' to vary the scene. The tree in the front has the same code as the background. It must be the height and width of the stage. Height is not a problem. Put a dot in the top left and right corners to make the tree sprite occupy the width of the stage. (See how this is done by looking inside the Sprite Editor).
The Bear 'grunt' is synced with its changing costume, A single bat clones itself when it touches the edge.