If you're not familiar with DragonRuby, you can check out a live demo here:<p><a href="http://fiddle.dragonruby.org.s3-website.us-east-2.amazonaws.com/index.html?tutorial=tutorial-arcade-shooter.html" rel="nofollow">http://fiddle.dragonruby.org.s3-website.us-east-2.amazonaws....</a>