JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/phaser/2.6.1/phaser.min.js"></script>
<div id="game-area">

</div>

JavaScript

var CANVAS_WIDTH = 600;
var CANVAS_HEIGHT = 400;

var game = new Phaser.Game(CANVAS_WIDTH, CANVAS_HEIGHT, Phaser.AUTO, 'phaser-example', { create: create, update: update, render: render });

var _platform;
var _player;
var _wall;
var _cursor;

function create(){
    //add cursor
    _cursor = game.input.keyboard.createCursorKeys();
    
    // set stage physics
    game.stage.backgroundColor = 0x808080;
    game.physics.startSystem(Phaser.Physics.ARCADE);
  
    _platform = fakeSprite(0, 300, 100, 20, '#0000dd');
    _player = fakeSprite(50, 200, 20, 20, '#0000dd');
    _wall = fakeSprite(200, 240, 50, 50, '#0000dd');
  
    game.physics.arcade.enable([_player, _platform, _wall]);
  
    _player.body.gravity.y = 500;
  
    _wall.body.immovable = true;
    _platform.body.immovable = true;
}

function update(){
    game.physics.arcade.collide(_player, _platform, CH_platform, null, this);
    game.physics.arcade.collide(_player, _wall, CH_wall, null, this);
    _platform.x += 0.2;
  
    // Move the player when an arrow key is pressed
    if (_cursor.left.isDown) {
        _player.body.velocity.x = -200;
    }else if (_cursor.right.isDown){
        _player.body.velocity.x = 200;
    }else {
        _player.body.velocity.x = 0;
    }

    // Make the player jump if he is touching the ground
    if (_cursor.up.isDown && _player.body.touching.down){
        _player.body.velocity.y = -250;
    }

}

function render(){

}

function CH_platform(obj1, obj2){
    obj1.x += 0.2;
    obj1.y = obj2.y-20;
}

function CH_wall(obj1, obj2){
    //obj1.x = obj2.x - 20;
}

function fakeSprite(x, y, w, h, c) {
    // create a new bitmap data object
    var bmd = game.add.bitmapData(w, h);

    // draw to the canvas context like normal
    bmd.ctx.beginPath();
    bmd.ctx.rect(0,0,w, h);
    bmd.ctx.fillStyle = c;
    bmd.ctx.fill();

    // draw arrow pointing to right
    bmd.ctx.beginPath();
    bmd.ctx.moveTo(0, (h/2));
    bmd.ctx.lineTo(w, (h/2)); // middle line
   ...