This is where all the replacement images and sounds go.  Some new files may also get created here.

Images:

-blank box.jpg: the image to use if a game has no box art.
-blank system.jpg: the image to use if the system has no art.
-icon.jpg: a 32x32 image used when selecting profiles - make this unique and do NOT make it larger than 32x32, it'll mess up the display in the profile selection screen.
-mainmenu.jpg: the image to use on the main menu - this must be 640x480, or it won't display properly.
-controller layout.jpg: the default controller layout to use if no other is supplied.  There is a generic black/gray one used, however if you put one in the profile directory, it will use it in place of the generic black/gray controller layout if no other one is found either in the system directory, or the game directory.

Sounds:

-snd_swap.wav: played when changing what is currently selected.
-snd_lock.wav: played when making a generic selection.
-snd_return.wav: played when going backward (escaping)
-snd_alert.wav: played when alert.txt exists in the directory for the selected game (rarely used)
-snd_alertdie.wav: played when an alert triggered by alert.txt is closed (rarely used)

Files:

-favorites.txt: created when adding to favorites if no favorites.txt exists.  contains the system directory and game directory for any favorited game.  if a game in favorites.txt no longer exists, it is not displayed in the launcher, but it is left in favorites.txt should it ever come back.