Show Gosu and Tk running side by side so we can add tradition UI along with Gosu apps.

gosu-tk.rb

require 'gosu'
require 'tk'

class GameWindow < Gosu::Window
  def initialize
    super 640, 480
    self.caption = "Gosu Tutorial Game"

    @frog = Gosu::Image.new("./frog_cling_1.png")
    @x = 0
  end

  def update
    @x += 1
  end

  def draw
    @frog.draw(@x,50,0)
  end
end

window = GameWindow.new
root = TkRoot.new { title "ex1" }

def update(window, root)
  window.tick
  root.update
end

TkLabel.new(root){ text "Hello World"; pack { padx 15; pady 15; side "left"; };}
while true do
  update(window, root)
end