HTML5 is being developed as the next major revision of HTML, the core markup language of the World Wide Web. Besides new elements like header, section, footer, etc., the HTML5 brings you the canvas element.
The canvas is a rectangular area within you can use Javascript to draw graphics or other visual images on a web page. Although HTML5 is not a W3C recommendation yet (because of cross browsers issues), people already started to play with it, and when I say play, I mean it.
Today I’ll share with you some awesome HTML5 games demos that show the HTML5 canvas potential.
Agent 008 Ball
Z-Type
RGB Invaders
Pacman
Spy Chase
Biolab Disaster
Wolfenstein 3D
Fred Jones in Adventureland
Asteroids
Crystal Galaxy
Same Game
Final words
A common misconception is that HTML 5 can provide animation within web pages, which is totallyuntrue. Either JavaScript or CSS3 (or both) is necessary for animating HTML elements.
Posted by: Dhiraj kumar
HTML5, CSS3, JQuery Tips & Tricks 
Have you seen boredtodeath.ie yet? It’s a full scale brawler all done in Impact JS and Create JS and rendered to the canvas. The version currently live also supports multiplayer co-op through Node JS and Socket IO