[list] [*] Improved lots of defence items [*] Rendering now uses sprite batches, grouping all sprites with the same image into one draw call [*] A texture atlas is created on startup, grouping all images into one massive image (4096x4096) [*] Various other rendering optimisations [*] Reorganised image files [*] Renderers are grouped into layers to be rendered, instead of being sorted [*] Chosen difficulty now saves properly [*] Difficulty icon is displayed in the proper location [*] Held items now follow the holder [*] There may be some graphics issues as a result of these optimisations [/list]