title: game performance of html5 canvas and pure Javascript/GWT
body: <p>I want to write an animated game which needs a lot of animations running all the time, something like rolling the cards/images in slot machine. I am wondering if I should mainly use just pure GWT/Javascript to run the animation, or use HTML5 Canvas or HTML5 animation to achieve this.
  I know I might be able to make more fancy animated motion or graphics if I use HTML5 canvas, but I also cares about the performance more because there are several "animations" running in the same time just like rolling so many images in 5 columns slot machine. In this case, I think performance is most important.</p>
  
  <p>I heard that drawing things in Canvas is really expensive. So I am not sure if I keep rolling images in Canvas is expensive as well. </p>
  
  <ol>
  <li><p>What do you think which technique I should use to write a game like slot machine? HTML5-Canvas, pure JS/GWT-animation, or HTML5-animation? </p></li>
  <li><p>I need to use some audio for the games, but I am pretty new to this, I do not know what libraries or technique I can use for audio. Please give me some advice.</p></li>
  </ol>
  
  <p>Thanks.</p>