you have exported the game and continue see the custom load page ?-> games html5 from c2 have manifest cache(for offline runnning)y when reload a exported game, the browser no show the changes ,then try to upload the version(properties)on the c2 project and re-export, or run the game on full clean browser.

Thanks for your help. Can I change the loading image?

yes, i add code to index.html for show custom load, when you re-export the game it will not be there.(see OnStartLayout event in prepare_ sheet)