This CodeProject article represents a port of a C# game to the modern web stack using the canvas element. It mainly focuses on how to create a reflection like environment that allows great flexibility for a game. Also this game decouples the graphic loop from the logic loop. Therefore the graphic context could be easily switched, e.g. to <div> elements with some CSS3 styles.
A live version of the Ultimate Tower Defense game is also available. At the moment I don't know how much more sophisticated I will make it. In the end a crucial question for me has been: How fast (and well) can I port this C# version, which has quite some dependencies (SDL.NET, DirectX, ...) to the webstack, without including any external dependencies?
The answer to this question (4 evenings) might be surprising, but I think a lot of experience is required to get it done within just a couple of days. Needless to say that this port is as fast and complete as the original version. It might be even more complete, flexible and it is - due to losing some dependencies on the way - more lightweight.