Added a tiled background image that I got from Open Game Art. It’s a small change, but it looks a lot better.

Tiled Background

  this.background = this.add.tileSprite(0, 0, this.cameras.main.width, this.cameras.main.height - 50, 'grass');
  this.background.setOrigin(0, 0)
  this.background.setDepth(-1)