​

function setup() {

  createCanvas(400, 400);

}

​

function draw() {

  if (gameStarted==false){

    startScreen();

  } else {

    gameScreen();

  }

}

​

function startScreen(){

  background(225)

  fill(0)

  text("click to start",150,200)

}

​

function gameScreen(){

  //game stuff goes here

  background(255,0,0)

}

​

function mousePressed(){

  gameStarted=true;

}