Ruby is a great scripting language, especially when you want to make the complex simple. Nothing is more complex than game programming... and few things are more simple than the Gosu game development library. This is a modification of the default tutorial/demo that comes with the library. I used the Ruby version, which required some additional downloads to support... but once it was done it worked wonderfully. (note: the Ruby version seems to have been developed more for Windows, and although using the source code to compile on other platforms is possible, my friend had to rewrite the make file for his Debian system)

The original demo created a window with a star field background, and allowed a ship to fly around picking up randomly generated jewels. Within a half hour, I had modified it to be more arcade like. The background scrolls down as if flying through space, the gems drop from the top to bottom and the ship moves from side to side. Scoring is based on the speed of the gem dropping and will count against you if missed. Nothing too exciting, but a good example of code on how animation, sound, movement, etc. is done in Gosu's Ruby library... and how easy it is to modify.

require 'gosu'

module ZOrder
  Background, Stars, Player, UI = *0..3
end

class Star
  attr_reader :x, :y, :kill, :speed
  attr_writer :kill
  
  def initialize(animation)
    @animation = animation
    @color = Gosu::Color.new(0xff000000)
    @color.red = rand(255 - 40) + 40
    @color.green = rand(255 - 40) + 40
    @color.blue = rand(255 - 40) + 40
    @x = rand * 640
    @y = 0
    @speed = (1+(rand*6)).round
    @kill = false
  end
  
  def draw
    @y = (@y+@speed) % 480
    img = @animation[Gosu::milliseconds / 100 % @animation.size];
    img.draw(@x - img.width / 2.0, @y - img.height / 2.0,
        ZOrder::Stars, 1, 1, @color, :additive)
  end
end

class Player
  def initialize(window)
    @image = Gosu::Image.new(window, "media/Starfighter.bmp", false)
    @beep = Gosu::Sample.new(window, "media/Beep.wav")
    @x = @y = @vel_x = @vel_y = @angle = 0.0
  end
  
  def warp(x, y)
    @x, @y = x, y
  end
  
  def turn_left
    @vel_x -= 1.5
  end
  
  def turn_right
    @vel_x += 1.5
  end
  
  def move
    if @vel_x.abs < 10 then
       @x += @vel_x
    else
        @x += 10*(@vel_x<=>0)
    end
    @x %= 640
    @vel_x *= 0.95
  end
  
  def collect_stars(stars)
    stars.reject! do |star|
      dist_x = @x - star.x
      dist_y = @y - star.y
      dist = Math.sqrt(dist_x * dist_x + dist_y * dist_y)
      if dist < 35 then
        yield star.speed*10
        @beep.play
        true
      else
        if star.kill then
         yield -star.speed*10
         true
        else
          false
        end
      end
    end
  end

  def draw
    @image.draw_rot(@x, @y, ZOrder::Player, @angle)
  end
end
  
class GameWindow < Gosu::Window
  def initialize
    super(640, 480, false, 20)
    self.caption = "Raiden v.0.1"
    
    @font = Gosu::Font.new(self, Gosu::default_font_name, 20)
    @background_image = Gosu::Image.new(self, "media/Space.png", true)
    @star_anim = Gosu::Image::load_tiles(self, "media/Star.png", 25, 25, false)
    
    @player = Player.new(self)
    @player.warp(320, 400)
    @stars = Array.new
    @score = 0
    @phase = 0
  end
  
  def update
    @phase = (@phase+2) % 480
    
    if button_down? Gosu::Button::KbLeft or button_down? Gosu::Button::GpLeft then
      @player.turn_left
    end
    if button_down? Gosu::Button::KbRight or button_down? Gosu::Button::GpRight then
      @player.turn_right
    end
    @player.move
    @player.collect_stars(@stars) { |gain| @score += gain }
    
    if rand(100) < 3 and @stars.size < 25 then
      @stars.push(Star.new(@star_anim))
    end
  end
  
  def button_down(id)
    if id == Gosu::Button::KbEscape
      close
    end
  end
  
  def draw
    @font.draw("Score: #{@score}", 10, 10, ZOrder::UI, 1.0, 1.0, 0xffffff00)
    @background_image.draw(0, @phase, ZOrder::Background)
    @background_image.draw(0, @phase-480, ZOrder::Background)
    @player.draw
    @stars.each { |star| if star.y > 470 then star.kill = true else star.draw end }
  end
  
end

GameWindow.new.show