Create a new file called mainmenu.lua and import Composer and the UI modules, the composer.newScene() function, and the variables for timer and audio:

local composer = require( "composer" )
local scene = Composer.newScene()

local ui = require("ui")

local btnAnim

local btnSound = audio.loadSound( "btnSound.wav" )

Create the create() event. Add in the composer.removeScene( "maingame" ) and composer.removeScene( "options" ) lines, which will remove the "maingame" and "options" scenes. You can remove "maingame" after the player has transitioned from the main game screen and is sent to the main menu screen. You can remove "options" after the player has transitioned from the options screen and is sent to the main menu screen:

-- Called when the scene's view does not exist:
function...