HTML5 games are not nearly as endangered as Flash games, and are in fact often cited as replacing the Flash medium. However, they still pose a risk of disappearing at some point in time, and therefore should be considered for curation just like other web game formats.
The following page is a tutorial on how to curate HTML5 games to add to Flashpoint.
Before You Start
This tutorial will assume you've read the standard Curation Tutorial, which is highly recommended to go through. Try curating a Flash game before moving on to HTML5.
Identifying HTML5 Games
If a web game doesn't ask to enable Adobe Flash Player and there's no sign or mention of any of the other Platforms, it is very likely an HTML5 game.
To confirm this, press F12 to open the Developer Tools of your browser and click the Network tab. Look for a .html file, likely with the filename "index.html". Copy the file's link and go to it. If it plays an unobstructed version of the game, you've found the source of your Launch Command.
Make sure to always use http:// instead of https:// to make sure Flashpoint grabs files from the fake Internet instead of the real one!
Grabbing The Game From The Internet
Use cURLsDownloader to create a content folder with your Launch Command. Simply copy the Launch Command's URL, open cURLsDownloader, paste in the URL, and hit Enter.
Moving The Game Into Flashpoint
Create a new curation in the Curate tab of Flashpoint Core and fill it out with as much information as you can, including the Launch Command you found earlier. The Platform should be
HTML5, and the Application Path should be
FPSoftware\Basilisk-Portable\Basilisk-Portable.exe, referring to the Basilisk browser used for HTML5 games.
Copy the content folder outputted by cURLsDownloader, select the "Open Folder" button on your curation in the Curate tab, and paste the folder into the "content" folder in your curation.
Test your game with the "Run" button. Don't be surprised if it doesn't work at first, because there are an extremely low number of HTML5 games that are single-asset. Your curation is almost guaranteed to be multi-asset. From here, you have two main options, both of which are described here.
Alternatively, if you don't want to jump back and forth between getting 404s and downloading them, you can use MAD4FP. Please be careful when using this, as it downloads every file requested by the game that still exists on the live web, meaning you can get a lot of files that are unnecessary for the game to work.
Wrapping It Up
Follow the proper Curation Format, just like with any curation.
Pack everything into a single .7z or .zip file and submit it to the #other-game-curations channel of the Flashpoint Discord. Use the HTML5 emoji when submitting.