If you are creating this for mobiles:
Try to reduce the overlapping area between them and never ever use large images. If you have a big object in the background, cut it into smaller images. Also crop all your images. The transparent/empty area counts as part of the image so it will use memory and cpu.
If you are creating this for desktop:
The same tips but you don't need to cut it too much I guess. And even if you didn't do all of this, your game should run easy in any desktop. 200mb of memory usage is nothing in a desktop.