platformer-create-3.js

function create() {
    this.add.image(400, 300, 'sky');

    var platforms = this.physics.add.staticGroup();

    platforms
        .create(400, 568, 'ground')
        .setScale(2)
        .refreshBody();

    platforms.create(600, 400, 'ground');
    platforms.create(50, 250, 'ground');
    platforms.create(750, 220, 'ground');

    player = this.physics.add.sprite(100, 450, 'dude');
    player.setBounce(0.2);
    player.setCollideWorldBounds(true);

    this.anims.create({
        key: 'left',
        frames: this.anims.generateFrameNumbers('dude', { start: 0, end: 3 }),
        frameRate: 10,
        repeat: -1,
    });

    this.anims.create({
        key: 'turn',
        frames: [{ key: 'dude', frame: 4 }],
        frameRate: 20,
    });

    this.anims.create({
        key: 'right',
        frames: this.anims.generateFrameNumbers('dude', { start: 5, end: 8 }),
        frameRate: 10,
        repeat: -1,
    });

    this.physics.add.collider(player, platforms);

    // Add this line of code below
    cursors = this.input.keyboard.createCursorKeys();
}