EVENT_GETMENUTILE is used to set a custom tile for the main menu background.
EXAMPLE:
gamevar MENU_TILE <flag> GAMEVAR_FLAG_GLOBAL onevent EVENT_GETMENUTILE setvar RETURN <tilenum> endevent
gamevar MENU_TILE is used to set whether the screen is one picture or if it is tiled, like a texture.
Values for <flag>:
In the onevent code, set the gamevar RETURN to the tile you want the main menu background to be.