Another issue is that with HTML5, as a developer AND user, you not only depend on yer native platform, but also on the browsers developers. This seems a little backwards to me, it is too much dependency.
Again, these issues need to be addressed ASAP by the HTML5 people if HTML5 really aims to be what it claims. Needless to say, native format 2D games all run fine on the three computers.
This is about HTML5 and it is not about C2, there's really nothing I can complain about this amazing tool. However, there's plenty that needs to be done to HTML5 and I really hope they resolve them.
EDIT: Also forgot, although it is possible to play HTML5 games offline, it is a hassle and surely much harder than installing an EXE game on a computer. A casual user is more than capable to install an executable on their computer, but how many are capable of setting up the computer for offline HTML5 gaming?