StefanN
This won't help with current players using the cached version, but for future versions if you add something like this to your splash screen or main menu it should force reloading the updated version
Browser: On update ready -> Browser: Reload
From the Manual:
[quote:ousyv8j6]On update ready
Triggered when the game is running from cache, but an updated version has finished downloading in the background. If the user is still on the game's menu or title screen, you may wish to prompt them to refresh the page (or just do it automatically) so the new version is loaded