I'm a fan of the idea so I broke my vow of RGSS silence to whip up a steaming pile of code.
module PAC
Menu_Picture = "MenuBackground"
end
class Scene_Menu < Scene_MenuBase
alias pac_picturemenu_start start
def start(*args)
pac_picturemenu_start(*args)
create_pac_picture
end
def create_status_window
return
end
def create_pac_picture
@background_sprite2 = Sprite.new
@background_sprite2.bitmap = Cache.picture(PAC::Menu_Picture)
end
end
Basically, you'll need to import the picture you want as the overlay picture in to the Pictures folder (set transparency and all that), and change Menu_Picture to the name of that image. Should work. Make sure the image you're using is the correct resolution, as I didn't put in options for placing the image in a specific spot. Just use a 640x480 image and position things as you will.
I hope this is what you're after.