Erik Moeller, a developer at browser maker Opera, has just released an HTML5 snapshot of his game Emberwind.
The demo enables users to direct the game's main character, but ladders and doors are not functional. The focus is here is, of course, on the word demo, as it shows the possibilities of running a game within a browser and how we may be playing video in a few years down the road. If you run the demo, notice the smooth background animation as well as integration of Google webfonts.
According to Moeller, this brief demo is about 11 MB in size and has been tested on Windows 7, Mac OS X, Ubuntu Linux and iOS with the current browser versions of Opera, IE, Firefox, Chrome and Safari.