main.js

//Lib
import Phaser from "phaser";

//Scenes
import playGame from "./playGame";

//Find the perfect ratio
let width           = 720;
let height          = 1280;
let perfectRatio    = width / height;

//Find the current screen ratio
let innerWidth      = window.innerWidth;
let innerHeight     = window.innerHeight;
let actualRatio     = innerWidth / innerHeight;

//Find the final width
width = Math.min(width*actualRatio/perfectRatio, 1280);

let gameConfig = {
    type: Phaser.AUTO,
    scale: {
        mode: Phaser.Scale.FIT,
        autoCenter: Phaser.Scale.CENTER_BOTH,
        parent: 'jumpingbox',
        width: width,
        height: height
    },
    physics: {
      default: 'arcade',
      matter: {
        gravity: {x:0, y:500},
        debug: true
      }
    },
    scene: playGame
};

let game = new Phaser.Game(gameConfig);