The only thing that bothers me is the movement of the ducks, it feels too "smooth", too realistic: the original was less "curvy", much more straight-line and brutal on direction changes (certainly a simple sign change on the constant directional increment when reaching a boundary). This creates a weird reversed uncanny valley effect.
I'll see your HTML5 + JS Duckhunt, and raise you a 3D virtual reality Duckhunt:<p><a href="http://vimeo.com/23367165" rel="nofollow">http://vimeo.com/23367165</a><p>(that's me in the lei halfway through, going on about 35 hours without sleep. Was my final project for <a href="http://graphics.cs.columbia.edu/courses/csw4172" rel="nofollow">http://graphics.cs.columbia.edu/courses/csw4172</a> the second semester of my senior year in college. And there are some technical inaccuracies in my partner's voiceover...mostly concerning the WiiMote). Something about that game captivates the heart.
Very cool. However, correct me if I'm wrong, but the only actual "HTML5" component in here is the <audio> tag, and -*-user-select from CSS3. Everything else is pre-HTML5.<p>Yes, I know "HTML5" is used as a catch-all for anything and everything dynamic on the web, but overall this is a very good implementation of an HTML5-like webapp.<p>Good job ;)