Custom Ease

class Example extends Phaser.Scene
{
    constructor()
    {
        super();
    }

    preload ()
    {
        this.load.setBaseURL('https://cdn.phaserfiles.com/v385');
        this.load.image('block', 'assets/sprites/block.png');
    }

    create ()
    {
        var marker = this.add.image(100, 300, 'block').setAlpha(0.3);
        var image = this.add.image(100, 300, 'block');

        this.tweens.add({
            targets: image,
            x: 600,
            duration: 3000,
            ease: function (t)
            {
                return Math.pow(Math.sin(t * 3), 3);
            },
            delay: 1000
        });
    }
}

const config = {
    type: Phaser.AUTO,
    width: 800,
    height: 600,
    backgroundColor: '#2d2d2d',
    parent: 'phaser-example',
    scene: Example
};

var game = new Phaser.Game(config);