```ruby
module Asteroids
  class PlayState < GameState

    def initialize
      @background = Gosu::Image.new($window,
        Utils.get_image_path('background.png'), false)
    end

    def draw
      @background.draw(0, 0, 0)
    end

    def update
    end

    def button_down(id)
    end

  end
end```

Add code to swich from play state to menu state.
user
```ruby
module Asteroids
  class PlayState < GameState

    def initialize
      @background = Gosu::Image.new($window,
        Utils.get_image_path('background.png'), false)
    end

    def draw
      @background.draw(0, 0, 0)
    end

    def update
    end

    def button_down(id)
      if id == Gosu::KbEscape
        Asteroids::GameState.switch(Asteroids::MenuState.instance)
      end
    end

  end
end```
assistant