"So what's in common with these two games? They're both originally mobile games." (Emphasis mine.)
The sad part is that once converted to HTML5 these games won't be able to run on many (most?) mobile devices. Current mobile browsers are too slow or non-standard to run HTML5 based games. The exception is iOS 5 powered devices (iPhone/iPad) since the browser now includes hardware acceleration for both HTML5 canvas and CSS3 animation transforms.
But I think Chrome for Android 4 (which I believe will replace stock Android browser eventually), IE10 for Windows 8 phones / tablets, and Firefox on B2G will change this. I've seen B2G already running mobile web games smoothly on Android hardware.
That's unlikely, mobile device lifecycles are way shorter than those of desktop computers. Even native game developers often don't target mobile devices that are outdated.
Many smartphone users are prevented from upgrading their firmware/OS. So even if the device lifecycles are shorter, developers cannot ignore legacy devices. If we look at the current Android stats for top entertainment app users:
The sad part is that once converted to HTML5 these games won't be able to run on many (most?) mobile devices. Current mobile browsers are too slow or non-standard to run HTML5 based games. The exception is iOS 5 powered devices (iPhone/iPad) since the browser now includes hardware acceleration for both HTML5 canvas and CSS3 animation transforms.
For more details, see Spaceport.io's recent HTML5 animation performance tests: http://spaceport.io/spaceport_perfmarks_report_2012_3.pdf